diff --git a/keepassxc-browser/_locales/en/messages.json b/keepassxc-browser/_locales/en/messages.json
index c2f723757..4144bad88 100644
--- a/keepassxc-browser/_locales/en/messages.json
+++ b/keepassxc-browser/_locales/en/messages.json
@@ -235,6 +235,18 @@
         "message": "user.id does not match the required length.",
         "description": "user.id does not match the required length."
     },
+    "errorMessagePasskeysEvalByCredentialNotSupported": {
+        "message": "evalByCredential is not supported at registration.",
+        "description": "evalByCredential is not supported at registration."
+    },
+    "errorMessagePasskeysEvalByCredentialNotEmpty": {
+        "message": "evalByCredential is not empty, but allowedCredentials is.",
+        "description": "evalByCredential is not empty, but allowedCredentials is."
+    },
+    "errorMessagePasskeysEvalByCredentialNotFound": {
+        "message": "Credential ID provided in evalByCredential not found.",
+        "description": "Credential ID provided in evalByCredential not found."
+    },
     "errorMessagePasskeysContextIsNotSecure": {
         "message": "Context is not secure.",
         "description": "Context is not secure."
diff --git a/keepassxc-browser/background/client.js b/keepassxc-browser/background/client.js
index 427aa3d3f..648ee7e60 100644
--- a/keepassxc-browser/background/client.js
+++ b/keepassxc-browser/background/client.js
@@ -44,6 +44,9 @@ const kpErrors = {
     PASSKEYS_UNKNOWN_ERROR: 31,
     PASSKEYS_INVALID_CHALLENGE: 32,
     PASSKEYS_INVALID_USER_ID: 33,
+    PASSKEYS_EVAL_BY_CREDENTIAL_NOT_SUPPORTED: 34,
+    PASSKEYS_EVAL_BY_CREDENTIAL_NOT_EMPTY: 35,
+    PASSKEYS_EVAL_BY_CREDENTIAL_NOT_FOUND: 36,
 
     errorMessages: {
         0: { msg: tr('errorMessageUnknown') },
@@ -80,6 +83,9 @@ const kpErrors = {
         31: { msg: tr('errorMessagePasskeysUnknownError') },
         32: { msg: tr('errorMessagePasskeysInvalidChallenge') },
         33: { msg: tr('errorMessagePasskeysInvalidUserId') },
+        34: { msg: tr('errorMessagePasskeysEvalByCredentialNotSupported') },
+        35: { msg: tr('errorMessagePasskeysEvalByCredentialNotEmpty') },
+        36: { msg: tr('errorMessagePasskeysEvalByCredentialNotFound') }
     },
 
     getError(errorCode) {
diff --git a/keepassxc-browser/content/passkeys-utils.js b/keepassxc-browser/content/passkeys-utils.js
index b28541251..3c808c888 100644
--- a/keepassxc-browser/content/passkeys-utils.js
+++ b/keepassxc-browser/content/passkeys-utils.js
@@ -63,6 +63,11 @@ kpxcPasskeysUtils.buildCredentialCreationOptions = function(pkOptions, sameOrigi
         publicKey.challenge = kpxcArrayBufferToBase64(pkOptions.challenge);
         publicKey.extensions = pkOptions?.extensions;
 
+        const prfSalt = publicKey?.extensions?.prf?.eval?.first;
+        if (prfSalt) {
+            publicKey.extensions.prf.eval.first = kpxcArrayBufferToBase64(prfSalt);
+        }
+
         // Make sure integers are used for "alg". Set to reserved if not found.
         // https://www.iana.org/assignments/cose/cose.xhtml#algorithms
         publicKey.pubKeyCredParams = [];
@@ -113,6 +118,11 @@ kpxcPasskeysUtils.buildCredentialRequestOptions = function(pkOptions, sameOrigin
         publicKey.timeout = getTimeout(publicKey?.userVerification, pkOptions?.timeout);
         publicKey.userVerification = pkOptions?.userVerification;
 
+        const prfSalt = publicKey?.extensions?.prf?.eval?.first;
+        if (prfSalt) {
+            publicKey.extensions.prf.eval.first = kpxcArrayBufferToBase64(prfSalt);
+        }
+
         publicKey.allowCredentials = [];
         if (pkOptions.allowCredentials && pkOptions.allowCredentials.length > 0) {
             for (const cred of pkOptions.allowCredentials) {
diff --git a/keepassxc-browser/content/passkeys.js b/keepassxc-browser/content/passkeys.js
index a516406f4..2b77124d2 100644
--- a/keepassxc-browser/content/passkeys.js
+++ b/keepassxc-browser/content/passkeys.js
@@ -15,6 +15,9 @@
     const PASSKEYS_UNKNOWN_ERROR = 31;
     const PASSKEYS_INVALID_CHALLENGE = 32;
     const PASSKEYS_INVALID_USER_ID = 33;
+    const PASSKEYS_EVAL_BY_CREDENTIAL_NOT_SUPPORTED = 34;
+    const PASSKEYS_EVAL_BY_CREDENTIAL_NOT_EMPTY = 35;
+    const PASSKEYS_EVAL_BY_CREDENTIAL_NOT_FOUND = 36;
 
     const kpxcStringToArrayBuffer = function(str) {
         const arr = Uint8Array.from(str, c => c.charCodeAt(0));
@@ -82,6 +85,17 @@
             getPublicKeyAlgorithm: () => publicKey.response?.publicKeyAlgorithm,
             getTransports: () => [ 'internal' ]
         };
+
+        const prfResponse = publicKey.response?.clientExtensionResults?.prf;
+        if (prfResponse) {
+            if (prfResponse?.results?.first) {
+                response['clientExtensionResults'] =
+                { prf: { results: { first: kpxcBase64ToArrayBuffer(prfResponse?.results?.first) } } };
+            } else if (prfResponse?.enabled) {
+                response['clientExtensionResults'] = { prf: prfResponse };
+            }
+        }
+
         return Object.setPrototypeOf(response, AuthenticatorAttestationResponse.prototype);
     };
 
@@ -94,6 +108,11 @@
             userHandle: publicKey.response?.userHandle ? kpxcBase64ToArrayBuffer(publicKey.response?.userHandle) : null
         };
 
+        const prfResponse = publicKey.response?.clientExtensionResults?.prf?.results?.first;
+        if (prfResponse) {
+            response['clientExtensionResults'] = { prf: { results: { first: kpxcBase64ToArrayBuffer(prfResponse) } } };
+        }
+
         return Object.setPrototypeOf(response, AuthenticatorAssertionResponse.prototype);
     };
 
@@ -102,14 +121,16 @@
         const authenticatorResponse = publicKey?.response?.attestationObject
             ? createAttestationResponse(publicKey)
             : createAssertionResponse(publicKey);
+        const clientExtensionResults =
+            authenticatorResponse?.clientExtensionResults || publicKey?.response?.clientExtensionResults || {};
         const publicKeyCredential = {
             authenticatorAttachment: publicKey.authenticatorAttachment,
             id: publicKey.id,
             rawId: kpxcBase64ToArrayBuffer(publicKey.id),
             response: authenticatorResponse,
             type: publicKey.type,
-            clientExtensionResults: () => publicKey?.response?.clientExtensionResults || {},
-            getClientExtensionResults: () => publicKey?.response?.clientExtensionResults || {},
+            clientExtensionResults: () => clientExtensionResults,
+            getClientExtensionResults: () => clientExtensionResults,
             toJSON: () => kpxcPublicKeyCredentialJson(publicKeyCredential, publicKey)
         };
 
@@ -179,10 +200,20 @@
             throw new DOMException(errorMessage, DOMException.SECURITY_ERR);
         }
 
-        if (errorCode === PASSKEYS_NO_SUPPORTED_ALGORITHMS) {
+        if (
+            [
+                PASSKEYS_NO_SUPPORTED_ALGORITHMS,
+                PASSKEYS_EVAL_BY_CREDENTIAL_NOT_SUPPORTED,
+                PASSKEYS_EVAL_BY_CREDENTIAL_NOT_EMPTY
+            ].includes(errorCode)
+        ) {
             throw new DOMException(errorMessage, DOMException.NOT_SUPPORTED_ERR);
         }
 
+        if (errorCode === PASSKEYS_EVAL_BY_CREDENTIAL_NOT_FOUND) {
+            throw new DOMException(errorMessage, DOMException.SYNTAX_ERR);
+        }
+
         if ([ PASSKEYS_INVALID_CHALLENGE, PASSKEYS_INVALID_USER_ID ].includes(errorCode)) {
             throw new TypeError(errorMessage);
         }