diff --git a/libkdecorations/kdecoration.h b/libkdecorations/kdecoration.h
index 0a20145e53..fb40259e23 100644
--- a/libkdecorations/kdecoration.h
+++ b/libkdecorations/kdecoration.h
@@ -1219,5 +1219,6 @@ inline int KDecoration::height() const
 /** @} */
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(KDecoration::QuickTileMode)
+Q_DECLARE_METATYPE(KDecorationDefines::WindowOperation)
 
 #endif
diff --git a/useractions.cpp b/useractions.cpp
index 232d301b52..afb6c74a03 100755
--- a/useractions.cpp
+++ b/useractions.cpp
@@ -770,7 +770,13 @@ void UserActionsMenu::slotWindowOperation(QAction *action)
     };
     if (!type.isEmpty())
         helperDialog(type, c);
-    Workspace::self()->performWindowOperation(c.data(), op);
+    // need to delay performing the window operation as we need to have the
+    // user actions menu closed before we destroy the decoration. Otherwise Qt crashes
+    qRegisterMetaType<KDecorationDefines::WindowOperation>();
+    QMetaObject::invokeMethod(workspace(), "performWindowOperation",
+                              Qt::QueuedConnection,
+                              Q_ARG(KWin::Client*, c.data()),
+                              Q_ARG(KDecorationDefines::WindowOperation, op));
 }
 
 void UserActionsMenu::slotSendToDesktop(QAction *action)
diff --git a/workspace.h b/workspace.h
index 6b67070506..b4d4a098c1 100644
--- a/workspace.h
+++ b/workspace.h
@@ -233,8 +233,6 @@ public:
     void updateOnAllDesktopsOfTransients(Client*);
     void checkTransients(xcb_window_t w);
 
-    void performWindowOperation(Client* c, WindowOperation op);
-
     void storeSession(KConfig* config, SMSavePhase phase);
     void storeClient(KConfigGroup &cg, int num, Client *c);
     void storeSubSession(const QString &name, QSet<QByteArray> sessionIds);
@@ -302,6 +300,7 @@ public:
     bool compositing() const;
 
 public Q_SLOTS:
+    void performWindowOperation(KWin::Client* c, KDecorationDefines::WindowOperation op);
     // Keybindings
     //void slotSwitchToWindow( int );
     void slotWindowToDesktop();