diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 3faf05a7e7..fc65e490ef 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -7254,6 +7254,11 @@ pqGetHomeDirectory(char *buf, int bufsize)
 /*
  * To keep the API consistent, the locking stubs are always provided, even
  * if they are not required.
+ *
+ * Since we neglected to provide any error-return convention in the
+ * pgthreadlock_t API, we can't do much except Assert upon failure of any
+ * mutex primitive.  Fortunately, such failures appear to be nonexistent in
+ * the field.
  */
 
 static void
@@ -7273,7 +7278,7 @@ default_threadlock(int acquire)
 		if (singlethread_lock == NULL)
 		{
 			if (pthread_mutex_init(&singlethread_lock, NULL))
-				PGTHREAD_ERROR("failed to initialize mutex");
+				Assert(false);
 		}
 		InterlockedExchange(&mutex_initlock, 0);
 	}
@@ -7281,12 +7286,12 @@ default_threadlock(int acquire)
 	if (acquire)
 	{
 		if (pthread_mutex_lock(&singlethread_lock))
-			PGTHREAD_ERROR("failed to lock mutex");
+			Assert(false);
 	}
 	else
 	{
 		if (pthread_mutex_unlock(&singlethread_lock))
-			PGTHREAD_ERROR("failed to unlock mutex");
+			Assert(false);
 	}
 #endif
 }
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 67feaedc4e..2ee5a0a40a 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -611,15 +611,20 @@ static pthread_mutex_t *pq_lockarray;
 static void
 pq_lockingcallback(int mode, int n, const char *file, int line)
 {
+	/*
+	 * There's no way to report a mutex-primitive failure, so we just Assert
+	 * in development builds, and ignore any errors otherwise.  Fortunately
+	 * this is all obsolete in modern OpenSSL.
+	 */
 	if (mode & CRYPTO_LOCK)
 	{
 		if (pthread_mutex_lock(&pq_lockarray[n]))
-			PGTHREAD_ERROR("failed to lock mutex");
+			Assert(false);
 	}
 	else
 	{
 		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			PGTHREAD_ERROR("failed to unlock mutex");
+			Assert(false);
 	}
 }
 #endif							/* ENABLE_THREAD_SAFETY && HAVE_CRYPTO_LOCK */
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index e81dc37906..6b7fd2c267 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -626,13 +626,6 @@ extern bool pqGetHomeDirectory(char *buf, int bufsize);
 #ifdef ENABLE_THREAD_SAFETY
 extern pgthreadlock_t pg_g_threadlock;
 
-#define PGTHREAD_ERROR(msg) \
-	do { \
-		fprintf(stderr, "%s\n", msg); \
-		abort(); \
-	} while (0)
-
-
 #define pglock_thread()		pg_g_threadlock(true)
 #define pgunlock_thread()	pg_g_threadlock(false)
 #else