diff --git a/src/kem/classic_mceliece/kem_classic_mceliece.h b/src/kem/classic_mceliece/kem_classic_mceliece.h
index 13613e7817..a8ee7df876 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece.h
+++ b/src/kem/classic_mceliece/kem_classic_mceliece.h
@@ -10,8 +10,8 @@
 #define OQS_KEM_classic_mceliece_348864_length_secret_key 6492
 #define OQS_KEM_classic_mceliece_348864_length_ciphertext 96
 #define OQS_KEM_classic_mceliece_348864_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_348864_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_348864_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_348864_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_348864_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_348864_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -25,8 +25,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864_decaps(uint8_t *shared_secret
 #define OQS_KEM_classic_mceliece_348864f_length_secret_key 6492
 #define OQS_KEM_classic_mceliece_348864f_length_ciphertext 96
 #define OQS_KEM_classic_mceliece_348864f_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_348864f_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_348864f_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_348864f_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_348864f_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_348864f_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864f_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -40,8 +40,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864f_decaps(uint8_t *shared_secre
 #define OQS_KEM_classic_mceliece_460896_length_secret_key 13608
 #define OQS_KEM_classic_mceliece_460896_length_ciphertext 156
 #define OQS_KEM_classic_mceliece_460896_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_460896_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_460896_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_460896_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_460896_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_460896_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -55,8 +55,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896_decaps(uint8_t *shared_secret
 #define OQS_KEM_classic_mceliece_460896f_length_secret_key 13608
 #define OQS_KEM_classic_mceliece_460896f_length_ciphertext 156
 #define OQS_KEM_classic_mceliece_460896f_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_460896f_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_460896f_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_460896f_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_460896f_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_460896f_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896f_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -70,8 +70,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896f_decaps(uint8_t *shared_secre
 #define OQS_KEM_classic_mceliece_6688128_length_secret_key 13932
 #define OQS_KEM_classic_mceliece_6688128_length_ciphertext 208
 #define OQS_KEM_classic_mceliece_6688128_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_6688128_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_6688128_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_6688128_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_6688128_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_6688128_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -85,8 +85,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128_decaps(uint8_t *shared_secre
 #define OQS_KEM_classic_mceliece_6688128f_length_secret_key 13932
 #define OQS_KEM_classic_mceliece_6688128f_length_ciphertext 208
 #define OQS_KEM_classic_mceliece_6688128f_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_6688128f_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_6688128f_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_6688128f_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_6688128f_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_6688128f_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128f_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -100,8 +100,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128f_decaps(uint8_t *shared_secr
 #define OQS_KEM_classic_mceliece_6960119_length_secret_key 13948
 #define OQS_KEM_classic_mceliece_6960119_length_ciphertext 194
 #define OQS_KEM_classic_mceliece_6960119_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_6960119_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_6960119_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_6960119_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_6960119_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_6960119_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -115,8 +115,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119_decaps(uint8_t *shared_secre
 #define OQS_KEM_classic_mceliece_6960119f_length_secret_key 13948
 #define OQS_KEM_classic_mceliece_6960119f_length_ciphertext 194
 #define OQS_KEM_classic_mceliece_6960119f_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_6960119f_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_6960119f_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_6960119f_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_6960119f_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_6960119f_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119f_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -130,8 +130,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119f_decaps(uint8_t *shared_secr
 #define OQS_KEM_classic_mceliece_8192128_length_secret_key 14120
 #define OQS_KEM_classic_mceliece_8192128_length_ciphertext 208
 #define OQS_KEM_classic_mceliece_8192128_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_8192128_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_8192128_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_8192128_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_8192128_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_8192128_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
@@ -145,8 +145,8 @@ OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128_decaps(uint8_t *shared_secre
 #define OQS_KEM_classic_mceliece_8192128f_length_secret_key 14120
 #define OQS_KEM_classic_mceliece_8192128f_length_ciphertext 208
 #define OQS_KEM_classic_mceliece_8192128f_length_shared_secret 32
-#define OQS_KEM_classic_mceliece_8192128f_length_keypair_seed 0
-#define OQS_KEM_classic_mceliece_8192128f_length_encaps_seed 0
+#define OQS_KEM_classic_mceliece_8192128f_length_keypair_seed 32
+#define OQS_KEM_classic_mceliece_8192128f_length_encaps_seed 32
 OQS_KEM *OQS_KEM_classic_mceliece_8192128f_new(void);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128f_keypair(uint8_t *public_key, uint8_t *secret_key);
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed);
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_348864.c b/src/kem/classic_mceliece/kem_classic_mceliece_348864.c
index 75206097a7..85706fce2f 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_348864.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_348864.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_348864_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_348864_avx2)
 extern int PQCLEAN_MCELIECE348864_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE348864_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE348864_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE348864_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_348864_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE348864_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE348864_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_348864f.c b/src/kem/classic_mceliece/kem_classic_mceliece_348864f.c
index 139510b659..8df61dc9b0 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_348864f.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_348864f.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_348864f_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_348864f_avx2)
 extern int PQCLEAN_MCELIECE348864F_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE348864F_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE348864F_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE348864F_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_348864f_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT) && OQS_CPU_has_extension(OQS_CPU_EXT_BMI1)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE348864F_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE348864F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_348864f_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_460896.c b/src/kem/classic_mceliece/kem_classic_mceliece_460896.c
index 76a6a5ad5c..dc25ab44e5 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_460896.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_460896.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_460896_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_460896_avx2)
 extern int PQCLEAN_MCELIECE460896_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE460896_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE460896_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE460896_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_460896_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE460896_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE460896_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_460896f.c b/src/kem/classic_mceliece/kem_classic_mceliece_460896f.c
index ac67c54b0b..dac5d9280c 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_460896f.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_460896f.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_460896f_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_460896f_avx2)
 extern int PQCLEAN_MCELIECE460896F_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE460896F_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE460896F_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE460896F_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_460896f_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT) && OQS_CPU_has_extension(OQS_CPU_EXT_BMI1)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE460896F_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE460896F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_460896f_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_6688128.c b/src/kem/classic_mceliece/kem_classic_mceliece_6688128.c
index 77345fa0b0..b46201e544 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_6688128.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_6688128.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_6688128_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_6688128_avx2)
 extern int PQCLEAN_MCELIECE6688128_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6688128_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6688128_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6688128_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_6688128_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE6688128_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE6688128_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_6688128f.c b/src/kem/classic_mceliece/kem_classic_mceliece_6688128f.c
index f7730bee55..f40cfdd556 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_6688128f.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_6688128f.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_6688128f_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_6688128f_avx2)
 extern int PQCLEAN_MCELIECE6688128F_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6688128F_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6688128F_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6688128F_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_6688128f_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT) && OQS_CPU_has_extension(OQS_CPU_EXT_BMI1)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE6688128F_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE6688128F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6688128f_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_6960119.c b/src/kem/classic_mceliece/kem_classic_mceliece_6960119.c
index a815e39050..a6b6a7ec30 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_6960119.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_6960119.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_6960119_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_6960119_avx2)
 extern int PQCLEAN_MCELIECE6960119_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6960119_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6960119_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6960119_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_6960119_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE6960119_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE6960119_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_6960119f.c b/src/kem/classic_mceliece/kem_classic_mceliece_6960119f.c
index 779592b490..eaf0416fe4 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_6960119f.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_6960119f.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_6960119f_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_6960119f_avx2)
 extern int PQCLEAN_MCELIECE6960119F_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE6960119F_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE6960119F_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE6960119F_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_6960119f_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT) && OQS_CPU_has_extension(OQS_CPU_EXT_BMI1)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE6960119F_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE6960119F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_6960119f_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_8192128.c b/src/kem/classic_mceliece/kem_classic_mceliece_8192128.c
index 35ce70d700..ff3580d1ea 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_8192128.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_8192128.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_8192128_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_8192128_avx2)
 extern int PQCLEAN_MCELIECE8192128_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE8192128_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE8192128_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE8192128_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_8192128_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE8192128_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE8192128_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/kem_classic_mceliece_8192128f.c b/src/kem/classic_mceliece/kem_classic_mceliece_8192128f.c
index 3166a9c457..a1c2e27feb 100644
--- a/src/kem/classic_mceliece/kem_classic_mceliece_8192128f.c
+++ b/src/kem/classic_mceliece/kem_classic_mceliece_8192128f.c
@@ -35,20 +35,31 @@ OQS_KEM *OQS_KEM_classic_mceliece_8192128f_new(void) {
 }
 
 extern int PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 
 #if defined(OQS_ENABLE_KEM_classic_mceliece_8192128f_avx2)
 extern int PQCLEAN_MCELIECE8192128F_AVX2_crypto_kem_keypair(uint8_t *pk, uint8_t *sk);
+extern int PQCLEAN_MCELIECE8192128F_AVX2_crypto_kem_keypair_derand(uint8_t *pk, uint8_t *sk, const uint8_t seed[32]);
 extern int PQCLEAN_MCELIECE8192128F_AVX2_crypto_kem_enc(uint8_t *ct, uint8_t *ss, const uint8_t *pk);
 extern int PQCLEAN_MCELIECE8192128F_AVX2_crypto_kem_dec(uint8_t *ss, const uint8_t *ct, const uint8_t *sk);
 #endif
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128f_keypair_derand(uint8_t *public_key, uint8_t *secret_key, const uint8_t *seed) {
-	(void)public_key;
-	(void)secret_key;
-	(void)seed;
-	return OQS_ERROR;
+#if defined(OQS_ENABLE_KEM_classic_mceliece_8192128f_avx2)
+#if defined(OQS_DIST_BUILD)
+	if (OQS_CPU_has_extension(OQS_CPU_EXT_AVX2) && OQS_CPU_has_extension(OQS_CPU_EXT_POPCNT) && OQS_CPU_has_extension(OQS_CPU_EXT_BMI1)) {
+#endif /* OQS_DIST_BUILD */
+		return (OQS_STATUS) PQCLEAN_MCELIECE8192128F_AVX2_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#if defined(OQS_DIST_BUILD)
+	} else {
+		return (OQS_STATUS) PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+	}
+#endif /* OQS_DIST_BUILD */
+#else
+	return (OQS_STATUS) PQCLEAN_MCELIECE8192128F_CLEAN_crypto_kem_keypair_derand(public_key, secret_key, seed);
+#endif
 }
 
 OQS_API OQS_STATUS OQS_KEM_classic_mceliece_8192128f_keypair(uint8_t *public_key, uint8_t *secret_key) {
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/crypto_kem.h
index 65a467af2a..d8a7e2c5df 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE348864_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/crypto_kem.h
index 5035f48418..b8a34be50d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE348864_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/crypto_kem.h
index 2e19227c8a..8550ac14b5 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE348864F_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/crypto_kem.h
index eea78ae12b..7a68782ee1 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE348864F_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece348864f_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/crypto_kem.h
index c9157864e8..99c832a43c 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE460896_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/crypto_kem.h
index cac52c93f0..68436c4f98 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE460896_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/crypto_kem.h
index 38c49f5d28..8982baebae 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE460896F_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/crypto_kem.h
index 58c52149f9..bcb74e51af 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE460896F_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece460896f_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/crypto_kem.h
index 2d863af3dc..da22cbbd46 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6688128_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/crypto_kem.h
index 91a1738006..bad4a4f338 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6688128_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/crypto_kem.h
index 814ac4f6f4..208f1428d2 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6688128F_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/crypto_kem.h
index e6e5caca82..1314236eb2 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6688128F_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6688128f_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/crypto_kem.h
index c19b2784e1..5248dc3cd9 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6960119_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.c
index 3aa78030d0..b92ab95f6a 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.c
@@ -136,6 +136,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -147,7 +159,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/crypto_kem.h
index d5ee59b2ce..34eb14dcc4 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6960119_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.c
index 3aa78030d0..b92ab95f6a 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.c
@@ -136,6 +136,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -147,7 +159,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/crypto_kem.h
index 4dc7f2a87b..647ccdea76 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6960119F_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.c
index 881a1cad75..57fc1de6dd 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.c
@@ -136,6 +136,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -148,7 +160,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/crypto_kem.h
index 160d9171d4..c117d6a731 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE6960119F_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.c
index 881a1cad75..57fc1de6dd 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.c
@@ -136,6 +136,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -148,7 +160,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece6960119f_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/crypto_kem.h
index 1d46061378..91b683999f 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE8192128_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/crypto_kem.h
index e9846d17cf..303cc12241 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE8192128_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.c
index 23479c8de8..14e6e826fe 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -88,7 +100,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/crypto_kem.h
index 7551476b37..ca7dbc073f 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE8192128F_AVX2_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.c b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.h b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_avx2/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/crypto_kem.h b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/crypto_kem.h
index 565f759740..e61d80d88b 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/crypto_kem.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/crypto_kem.h
@@ -2,6 +2,7 @@
 #define PQCLEAN_MCELIECE8192128F_CLEAN_CRYPTO_KEM_H
 
 #define crypto_kem_keypair CRYPTO_NAMESPACE(crypto_kem_keypair)
+#define crypto_kem_keypair_derand CRYPTO_NAMESPACE(crypto_kem_keypair_derand)
 #define crypto_kem_enc CRYPTO_NAMESPACE(crypto_kem_enc)
 #define crypto_kem_dec CRYPTO_NAMESPACE(crypto_kem_dec)
 
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.c b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.c
index 90e8082d9b..8553693e49 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.c
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.c
@@ -77,6 +77,18 @@ int crypto_kem_keypair
 (
     unsigned char *pk,
     unsigned char *sk
+)
+{
+    unsigned char seed[32] = {};
+    randombytes(seed, 32);
+    return crypto_kem_keypair_derand(pk, sk, seed);
+}
+
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char input_seed[32]
 ) {
     int i;
     unsigned char seed[ 33 ] = {64};
@@ -89,7 +101,7 @@ int crypto_kem_keypair
     uint32_t perm[ 1 << GFBITS ]; // random permutation as 32-bit integers
     int16_t pi[ 1 << GFBITS ]; // random permutation
 
-    randombytes(seed + 1, 32);
+    memcpy(&seed[1], input_seed, 32);
 
     while (1) {
         rp = &r[ sizeof(r) - 32 ];
diff --git a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.h b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.h
index fa34d033a4..b1a3891a2d 100644
--- a/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.h
+++ b/src/kem/classic_mceliece/pqclean_mceliece8192128f_clean/operations.h
@@ -23,4 +23,11 @@ int crypto_kem_keypair
     unsigned char *sk
 );
 
+int crypto_kem_keypair_derand
+(
+    unsigned char *pk,
+    unsigned char *sk,
+    const unsigned char seed[32]
+);
+
 #endif