diff --git a/src/blackcore/simulator.h b/src/blackcore/simulator.h
index 48fc9f026..ce431d721 100644
--- a/src/blackcore/simulator.h
+++ b/src/blackcore/simulator.h
@@ -51,8 +51,6 @@ namespace BlackCore
         };
         Q_DECLARE_FLAGS(SimulatorStatus, SimulatorStatusFlag)
 
-        Q_DECLARE_FLAGS(SimulatorStatus, SimulatorStatusFlag)
-
         //! Render all aircraft if number of aircraft >= MaxAircraftInfinite
         const int MaxAircraftInfinite = 100;