diff --git a/Make b/Make
index 8212813741..5b1528ea6f 100755
--- a/Make
+++ b/Make
@@ -37,7 +37,7 @@ while case $# in 0) break ;; esac
 do 
 	case "$1" in
 	-pedantic)
-		O="$O -Werror -Wall -ansi -pedantic -std=c99 -D_XOPEN_SOURCE=600"
+		O="$O -Werror -Wall -Wold-style-definition -ansi -pedantic -std=c99"
 		;;
 	--)
 		shift