diff --git a/modules/simpletest/simpletest.install b/modules/simpletest/simpletest.install
index 75f6c9fe2fe910783ad3b6e06e69612d5a9bd43f..443f0e3753ce2d1211bab3615a357cb0e699ac46 100644
--- a/modules/simpletest/simpletest.install
+++ b/modules/simpletest/simpletest.install
@@ -200,7 +200,7 @@ function simpletest_schema() {
     ),
     'primary key' => array('message_id'),
     'indexes' => array(
-      'reporter' => array('test_class, message_id'),
+      'reporter' => array('test_class', 'message_id'),
     ),
   );
   $schema['simpletest_test_id'] = array(