--- a/pjlib/src/pj/os_core_unix.c
+++ b/pjlib/src/pj/os_core_unix.c
@@ -1139,7 +1139,7 @@ static pj_status_t init_mutex(pj_mutex_t
 	return PJ_RETURN_OS_ERROR(rc);
 
     if (type == PJ_MUTEX_SIMPLE) {
-#if (defined(PJ_LINUX) && PJ_LINUX!=0) || \
+#if (defined(PJ_LINUX) && PJ_LINUX!=0 && defined(__GLIBC__)) || \
     defined(PJ_HAS_PTHREAD_MUTEXATTR_SETTYPE)
 	rc = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
 #elif (defined(PJ_RTEMS) && PJ_RTEMS!=0) || \
@@ -1149,7 +1149,7 @@ static pj_status_t init_mutex(pj_mutex_t
 	rc = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
 #endif
     } else {
-#if (defined(PJ_LINUX) && PJ_LINUX!=0) || \
+#if (defined(PJ_LINUX) && PJ_LINUX!=0 && defined(__GLIBC__)) || \
      defined(PJ_HAS_PTHREAD_MUTEXATTR_SETTYPE)
 	rc = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
 #elif (defined(PJ_RTEMS) && PJ_RTEMS!=0) || \