diff --git a/effects.cpp b/effects.cpp
index 5ccf94f6c8..46409e3652 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -599,10 +599,12 @@ void EffectsHandlerImpl::slotUnmanagedShown(KWin::Toplevel *t)
     emit windowAdded(u->effectWindow());
 }
 
-void EffectsHandlerImpl::slotWindowClosed(KWin::Toplevel *c)
+void EffectsHandlerImpl::slotWindowClosed(KWin::Toplevel *c, KWin::Deleted *d)
 {
     c->disconnect(this);
-    emit windowClosed(c->effectWindow());
+    if (d) {
+        emit windowClosed(c->effectWindow());
+    }
 }
 
 void EffectsHandlerImpl::slotClientModalityChanged()
diff --git a/effects.h b/effects.h
index e607c11116..c2e0221429 100644
--- a/effects.h
+++ b/effects.h
@@ -245,7 +245,7 @@ protected Q_SLOTS:
     void slotClientShown(KWin::Toplevel*);
     void slotShellClientShown(KWin::Toplevel*);
     void slotUnmanagedShown(KWin::Toplevel*);
-    void slotWindowClosed(KWin::Toplevel *c);
+    void slotWindowClosed(KWin::Toplevel *c, KWin::Deleted *d);
     void slotClientMaximized(KWin::AbstractClient *c, MaximizeMode maxMode);
     void slotOpacityChanged(KWin::Toplevel *t, qreal oldOpacity);
     void slotClientModalityChanged();