diff --git a/vm/Config.macosx.x86.64 b/vm/Config.macosx.x86.64
index e2063c4a75..7ef5f89559 100644
--- a/vm/Config.macosx.x86.64
+++ b/vm/Config.macosx.x86.64
@@ -1,3 +1,3 @@
 include vm/Config.macosx
 include vm/Config.x86.64
-CFLAGS += -arch x86_64
+CFLAGS += -m64