--- UserCode/L1RpcTriggerAnalysis/interface/L1Obj.h	2013/05/17 13:02:11	1.7
+++ UserCode/L1RpcTriggerAnalysis/interface/L1Obj.h	2013/05/20 10:27:29	1.8
@@ -12,7 +12,7 @@ struct L1Obj : public TObject {
   TYPE  type;
 
   L1Obj() : pt(0.),eta(0.),phi(0.),bx(0),q(-1), type(NONE) {}
-  bool isValid() { return q >= 0;}
+  bool isValid() const { return q >= 0;}
 
   friend ostream & operator<< (ostream &out, const L1Obj &o);