diff --git a/libstdc++-v3/include/bits/mutex.h b/libstdc++-v3/include/bits/mutex.h
index 43f5b0b..7f88821 100644
--- a/libstdc++-v3/include/bits/mutex.h
+++ b/libstdc++-v3/include/bits/mutex.h
@@ -63,7 +63,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     typedef __gthread_mutex_t			__native_type;
 
 #ifdef __GTHREAD_MUTEX_INIT
+# if _GLIBCXX_ASSERTIONS && defined(PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP)
+    // Use an error-checking mutex type when assertions are enabled.
+    __native_type  _M_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
+# else
     __native_type  _M_mutex = __GTHREAD_MUTEX_INIT;
+# endif
 
     constexpr __mutex_base() noexcept = default;
 #else