diff --git a/cdist/conf/type/__timezone/manifest b/cdist/conf/type/__timezone/manifest
index 76fa5c97..81de0217 100755
--- a/cdist/conf/type/__timezone/manifest
+++ b/cdist/conf/type/__timezone/manifest
@@ -34,5 +34,6 @@ case "$os" in
     ;;
     *)
         echo "Unsupported OS $os" >&2
+        exit 1
     ;;
 esac