diff --git a/modules/gallery_unit_test/helpers/diff.php b/modules/gallery_unit_test/helpers/diff.php
new file mode 100644
index 00000000..1ea16fa6
--- /dev/null
+++ b/modules/gallery_unit_test/helpers/diff.php
@@ -0,0 +1,26 @@
+<?php defined("SYSPATH") or die("No direct script access.");
+/**
+ * Gallery - a web based photo album viewer and editor
+ * Copyright (C) 2000-2009 Bharat Mediratta
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+class diff_Core {
+  public function compare($a, $b) {
+    fwrite(fopen($a_name = tempnam("/tmp", "test"), "w"), $a);
+    fwrite(fopen($b_name = tempnam("/tmp", "test"), "w"), $b);
+    return `diff $a_name $b_name`;
+  }
+}