diff --git a/packages/oauth/src/install-provider.ts b/packages/oauth/src/install-provider.ts
index 1e1eddb14..affe47186 100644
--- a/packages/oauth/src/install-provider.ts
+++ b/packages/oauth/src/install-provider.ts
@@ -401,10 +401,10 @@ export class InstallProvider {
         res.end(body);
       }
     } catch (e: unknown) {
-      const message = `An unhandled error occurred while processing an install path request (error: ${e})`;
+      const errorMessage = e instanceof Error ? e.message : String(e);
+      const message = `An unhandled error occurred while processing an install path request (error: ${errorMessage})`;
       this.logger.error(message);
-      // biome-ignore lint/suspicious/noExplicitAny: errors can be any
-      throw new GenerateInstallUrlError((e as any).message);
+      throw new GenerateInstallUrlError(errorMessage);
     }
   }
 
diff --git a/packages/web-api/src/WebClient.ts b/packages/web-api/src/WebClient.ts
index e212cf5dd..3dcb7552c 100644
--- a/packages/web-api/src/WebClient.ts
+++ b/packages/web-api/src/WebClient.ts
@@ -799,7 +799,12 @@ export class WebClient extends Methods {
       // if it isn't a Gzip response but is from the admin.analytics.getFile request,
       // decode the ArrayBuffer to JSON read the error
       const buffer = await response.arrayBuffer();
-      data = JSON.parse(new TextDecoder().decode(buffer));
+      try {
+        data = JSON.parse(new TextDecoder().decode(buffer));
+      } catch (_) {
+        // failed to parse the response body as JSON
+        data = { ok: false, error: new TextDecoder().decode(buffer) };
+      }
     } else {
       const text = await response.text();
       try {
diff --git a/packages/webhook/src/IncomingWebhook.ts b/packages/webhook/src/IncomingWebhook.ts
index ba19ee2f6..e417cca65 100644
--- a/packages/webhook/src/IncomingWebhook.ts
+++ b/packages/webhook/src/IncomingWebhook.ts
@@ -71,7 +71,7 @@ export class IncomingWebhook {
       timeout: 0,
     },
   ) {
-    if (url === undefined) {
+    if (!url) {
       throw new Error('Incoming webhook URL is required');
     }