diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index cc3fee8bf6a..4594cbace40 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -2167,7 +2167,7 @@ function xmldb_main_upgrade($oldversion) {
         $table = new xmldb_table('message_user_actions');
 
         // Conditionally launch add index.
-        $index = new xmldb_index('userid_messageid_action', XMLDB_INDEX_UNIQUE, array('userid, messageid, action'));
+        $index = new xmldb_index('userid_messageid_action', XMLDB_INDEX_UNIQUE, array('userid', 'messageid', 'action'));
         if (!$dbman->index_exists($table, $index)) {
             $dbman->add_index($table, $index);
         }
@@ -2181,7 +2181,7 @@ function xmldb_main_upgrade($oldversion) {
         $table = new xmldb_table('messages');
 
         // Conditionally launch add index.
-        $index = new xmldb_index('conversationid_timecreated', XMLDB_INDEX_NOTUNIQUE, array('conversationid, timecreated'));
+        $index = new xmldb_index('conversationid_timecreated', XMLDB_INDEX_NOTUNIQUE, array('conversationid', 'timecreated'));
         if (!$dbman->index_exists($table, $index)) {
             $dbman->add_index($table, $index);
         }