diff --git a/composite.cpp b/composite.cpp
index 5ffae47277..25859793da 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -372,14 +372,20 @@ void Workspace::setupOverlay( Window w )
     assert( Extensions::shapeInputAvailable());
     XShapeCombineRectangles( display(), overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted );
     if( w != None )
-        {
         XShapeCombineRectangles( display(), w, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted );
-        XMapWindow( display(), w );
-        }
-    XMapRaised( display(), overlay );
     XSelectInput( display(), overlay, VisibilityChangeMask );
     }
 
+void Workspace::showOverlay()
+    {
+    assert( overlay != None );
+    if( overlay_shown )
+        return;
+    XMapSubwindows( display(), overlay );
+    XMapWindow( display(), overlay );
+    overlay_shown = true;
+    }
+
 void Workspace::destroyOverlay()
     {
     if( overlay == None )
@@ -388,6 +394,7 @@ void Workspace::destroyOverlay()
     XCompositeReleaseOverlayWindow( display(), overlay );
 #endif
     overlay = None;
+    overlay_shown = false;
     }
 
 //****************************************
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index 92ec98ffd5..5e6db2324f 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -638,6 +638,8 @@ void SceneOpenGL::waitSync()
 // actually paint to the screen (double-buffer swap or copy from pixmap buffer)
 void SceneOpenGL::flushBuffer( int mask, QRegion damage )
     {
+    if( wspace->overlayWindow()) // show the window only after the first pass, since
+        wspace->showOverlay();   // that pass may take long
     if( db )
         {
         if( mask & PAINT_SCREEN_REGION )
diff --git a/scene_xrender.cpp b/scene_xrender.cpp
index 097155ea51..ede5d47ad4 100644
--- a/scene_xrender.cpp
+++ b/scene_xrender.cpp
@@ -170,6 +170,8 @@ void SceneXrender::paint( QRegion damage, ToplevelList toplevels )
         }
     int mask = 0;
     paintScreen( &mask, &damage );
+    if( wspace->overlayWindow()) // show the window only after the first pass, since
+        wspace->showOverlay();   // that pass may take long
     if( mask & PAINT_SCREEN_REGION )
         {
         // Use the damage region as the clip region for the root window
diff --git a/workspace.cpp b/workspace.cpp
index b9965c2ab1..35ef19fd49 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -137,6 +137,7 @@ Workspace::Workspace( bool restore )
     compositeRate( 0 ),
     overlay( None ),
     overlay_visible( true ),
+    overlay_shown( false ),
     transSlider( NULL ),
     transButton( NULL )
     {
diff --git a/workspace.h b/workspace.h
index 814bb135c6..2bcbcaa19d 100644
--- a/workspace.h
+++ b/workspace.h
@@ -318,6 +318,7 @@ class Workspace : public QObject, public KDecorationDefines
         bool createOverlay();
         // init overlay and the destination window in it
         void setupOverlay( Window window );
+        void showOverlay();
         // destroys XComposite overlay window
         void destroyOverlay();
         Window overlayWindow();
@@ -723,6 +724,7 @@ class Workspace : public QObject, public KDecorationDefines
         QRegion repaints_region;
         Window overlay; // XComposite overlay window
         bool overlay_visible;
+        bool overlay_shown; // for showOverlay()
         QSlider *transSlider;
         QPushButton *transButton;