Index: agent/polkitqt1-agent-listener.cpp
===================================================================
--- agent/polkitqt1-agent-listener.cpp	(revision 1183495)
+++ agent/polkitqt1-agent-listener.cpp	(working copy)
@@ -66,7 +66,8 @@
     qDebug("Destroying listener");
 
     ListenerAdapter::instance()->removeListener(this);
-    g_object_unref(d->listener);
+    if (d->listener != NULL)
+        g_object_unref(d->listener);
 }
 
 bool Listener::registerListener(PolkitQt1::Subject *subject, const QString &objectPath)