diff --git a/py/asmx64.c b/py/asmx64.c
index c542df5089..c425034ba0 100644
--- a/py/asmx64.c
+++ b/py/asmx64.c
@@ -7,7 +7,7 @@
 #include "misc.h"
 #include "asmx64.h"
 
-#if defined(__OpenBSD__)
+#if defined(__OpenBSD__) || defined(__MACH__)
 #define MAP_ANONYMOUS MAP_ANON
 #endif