diff --git a/sdl-config.in b/sdl-config.in
index 95f4c9e8a..ef278fd6c 100644
--- a/sdl-config.in
+++ b/sdl-config.in
@@ -16,7 +16,7 @@ fi
 
 while test $# -gt 0; do
   case "$1" in
-  -*=*) optarg=`echo "$1" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
+  -*=*) optarg=`echo "$1" | LC_ALL="C" sed 's/[-_a-zA-Z0-9]*=//'` ;;
   *) optarg= ;;
   esac