diff --git a/include/class.ostsession.php b/include/class.ostsession.php
index 55c12493297b1a803810526c6dd09bf9655d993f..303b9d1c51cf625c7226091432aa88d3ed0129b6 100644
--- a/include/class.ostsession.php
+++ b/include/class.ostsession.php
@@ -228,7 +228,7 @@ extends SessionBackend {
     }
 
     function destroy($id){
-        return SessionData::objects()->filter(['session_id' => $id])->delete();
+        return (SessionData::objects()->filter(['session_id' => $id])->delete());
     }
 
     function cleanup() {