diff --git a/session_api.module b/session_api.module
index 016f8b9..c5c02f3 100644
--- a/session_api.module
+++ b/session_api.module
@@ -112,6 +112,6 @@ function session_api_cron() {
   }
   if (!empty($outdated_sids)) {
     module_invoke_all('session_api_cleanup', $outdated_sids);
-    db_query('DELETE FROM {session_api} WHERE sid IN (' . implode(',', $outdated_sids) . ')');
+    db_query('DELETE FROM {session_api} WHERE sid IN (:sids)', array(':sids' => $outdated_sids));
   }
 }