diff --git a/src/cmd/INIT/cc.darwin b/src/cmd/INIT/cc.darwin
index ef081a0b4..2af08a00d 100755
--- a/src/cmd/INIT/cc.darwin
+++ b/src/cmd/INIT/cc.darwin
@@ -27,7 +27,7 @@ do	case $op in
 		;;
 	-lm)	continue
 		;;
-	-O)	continue
+	-O)	arg='-Os'  # default to small code: Apple compiles its /bin/ksh with -Os
 		;;
 	esac
 	set "$@" "$arg"