diff --git a/simgear/structure/subsystem_mgr.cxx b/simgear/structure/subsystem_mgr.cxx
index 9ae7d706..3be90962 100644
--- a/simgear/structure/subsystem_mgr.cxx
+++ b/simgear/structure/subsystem_mgr.cxx
@@ -224,8 +224,7 @@ SGSubsystemGroup::Member::Member (const Member &)
 
 SGSubsystemGroup::Member::~Member ()
 {
-                                // FIXME: causes a crash
-//     delete subsystem;
+    delete subsystem;
 }
 
 void
diff --git a/simgear/threads/SGQueue.hxx b/simgear/threads/SGQueue.hxx
index 532106bf..9f534ec9 100644
--- a/simgear/threads/SGQueue.hxx
+++ b/simgear/threads/SGQueue.hxx
@@ -183,7 +183,7 @@ public:
     /**
      * Destroy this queue.
      */
-    ~SGBlockingQueue() { mutex.unlock(); }
+    ~SGBlockingQueue() {}
 
     /**
      *