diff --git a/t/t1001-read-tree-m-2way.sh b/t/t1001-read-tree-m-2way.sh
index 88c524f655..59b8e56058 100755
--- a/t/t1001-read-tree-m-2way.sh
+++ b/t/t1001-read-tree-m-2way.sh
@@ -363,7 +363,7 @@ test_expect_success 'a/b (untracked) vs a case setup.' '
 test_expect_success 'a/b (untracked) vs a, plus c/d case test.' '
 	read_tree_u_must_fail -u -m "$treeH" "$treeM" &&
 	git ls-files --stage &&
-	test -f a/b
+	test_path_is_file a/b
 '
 
 test_expect_success 'read-tree supports the super-prefix' '