--- /dev/null
+--- 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) || \