diff --git a/tests/RUNNING_TESTS.txt b/tests/RUNNING_TESTS.txt
index c80c42a83d..b976545c22 100644
--- a/tests/RUNNING_TESTS.txt
+++ b/tests/RUNNING_TESTS.txt
@@ -37,6 +37,12 @@ options can be found on the wiki (see below).
     $dbuser = 'user';
     $dbpasswd = 'password';
 
+It is possible to have multiple test_config.php files, for example if you
+are testing on multiple databases. You can specify which test_config.php file
+to use in the environment as follows:
+
+    $ PHPBB_TEST_CONFIG=tests/test_config.php phpunit
+
 Alternatively you can specify parameters in the environment, so e.g. the
 following will run phpunit with the same parameters as in the shown
 test_config.php file:
diff --git a/tests/test_framework/phpbb_test_case_helpers.php b/tests/test_framework/phpbb_test_case_helpers.php
index b46c36efaa..2a3c27f9f9 100644
--- a/tests/test_framework/phpbb_test_case_helpers.php
+++ b/tests/test_framework/phpbb_test_case_helpers.php
@@ -58,9 +58,19 @@ class phpbb_test_case_helpers
 			));
 		}
 
-		if (file_exists(dirname(__FILE__) . '/../test_config.php'))
+		if (isset($_SERVER['PHPBB_TEST_CONFIG']))
 		{
-			include(dirname(__FILE__) . '/../test_config.php');
+			// Could be an absolute path
+			$test_config = $_SERVER['PHPBB_TEST_CONFIG'];
+		}
+		else
+		{
+			$test_config = dirname(__FILE__) . '/../test_config.php';
+		}
+
+		if (file_exists($test_config))
+		{
+			include($test_config);
 
 			$config = array_merge($config, array(
 				'dbms'		=> $dbms,