diff --git a/cake/tests/lib/cake_test_suite_dispatcher.php b/cake/tests/lib/cake_test_suite_dispatcher.php
index cbbd6d4a6db..8b30cb6fa59 100644
--- a/cake/tests/lib/cake_test_suite_dispatcher.php
+++ b/cake/tests/lib/cake_test_suite_dispatcher.php
@@ -76,7 +76,8 @@ class CakeTestSuiteDispatcher {
  */
 	function CakeTestSuiteDispatcher() {
 		$this->_baseUrl = $_SERVER['PHP_SELF'];
-		$this->_baseDir = dirname($this->_baseUrl) . '/';
+		$dir = dirname($this->_baseUrl);
+		$this->_baseDir = ($dir === '/') ? $dir : $dir . '/';
 	}
 
 /**