t6120: fix under gettext-poison

index 4668f0058e..3e3fb462a0 100755
@@ -341,7 +341,7 @@ test_expect_success 'describe directly tagged blob' '
 test_expect_success 'describe tag object' '
 	git tag test-blob-1 -a -m msg unique-file:file &&
 	test_must_fail git describe test-blob-1 2>actual &&
-	grep "fatal: test-blob-1 is neither a commit nor blob" actual
+	test_i18ngrep "fatal: test-blob-1 is neither a commit nor blob" actual
 '
 
 test_expect_failure ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '