diff --git a/src/os_mac.h b/src/os_mac.h
index c13a301..28627f3 100644
--- a/src/os_mac.h
+++ b/src/os_mac.h
@@ -139,6 +139,9 @@
 #ifndef SYS_OPTWIN_FILE
 #  define SYS_OPTWIN_FILE "$VIMRUNTIME/optwin.vim"
 #endif
+#ifndef VIM_DEFAULTS_FILE
+#  define VIM_DEFAULTS_FILE "$VIMRUNTIME/defaults.vim"
+#endif
 #ifndef EVIM_FILE
 #  define EVIM_FILE	"$VIMRUNTIME/evim.vim"
 #endif