diff --git a/t/t3901-i18n-patch.sh b/t/t3901-i18n-patch.sh
index 7655da3f8d..b04f74aa71 100755
--- a/t/t3901-i18n-patch.sh
+++ b/t/t3901-i18n-patch.sh
@@ -19,7 +19,7 @@ check_encoding () {
 		8859)
 			grep "^encoding ISO-8859-1" ;;
 		*)
-			! grep "^encoding ISO-8859-1" ;;
+			grep "^encoding ISO-8859-1"; test "$?" != 0 ;;
 		esac || {
 			bad=1
 			break