diff --git a/runtime/internal/monitor.c b/runtime/internal/monitor.c
index 87afef54..7cdd394c 100644
--- a/runtime/internal/monitor.c
+++ b/runtime/internal/monitor.c
@@ -12,7 +12,7 @@
 #include <assert.h>
 
 #if _WIN32
-#elif linux
+#elif linux || __APPLE__
 #define USE_PTHREADS	1
 #else
 #endif