diff --git a/simgear/structure/event_mgr.hxx b/simgear/structure/event_mgr.hxx
index 4c8d29bd..4c89b060 100644
--- a/simgear/structure/event_mgr.hxx
+++ b/simgear/structure/event_mgr.hxx
@@ -63,6 +63,7 @@ class SGEventMgr : public SGSubsystem
 {
 public:
     SGEventMgr() { _freezeProp = 0; }
+    ~SGEventMgr() { _freezeProp = 0; }
 
     virtual void init() {}
     virtual void update(double delta_time_sec);