diff --git a/openmp/runtime/src/kmp_wrapper_getpid.h b/openmp/runtime/src/kmp_wrapper_getpid.h
--- a/openmp/runtime/src/kmp_wrapper_getpid.h
+++ b/openmp/runtime/src/kmp_wrapper_getpid.h
@@ -22,7 +22,7 @@
 #include <unistd.h>
 #if KMP_OS_DARWIN
 // OS X
-#define __kmp_gettid() syscall(SYS_thread_selfid)
+#define __kmp_gettid() pthread_mach_thread_np(pthread_self())
 #elif KMP_OS_FREEBSD
 #include <pthread_np.h>
 #define __kmp_gettid() pthread_getthreadid_np()