diff --git a/effects.cpp b/effects.cpp
index 98df05e0a0..f847570fb5 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -324,6 +324,25 @@ bool EffectsHandlerImpl::hasKeyboardGrab() const
     return keyboard_grab_effect != NULL;
     }
 
+void EffectsHandlerImpl::propertyNotify( EffectWindow* c, long atom )
+    {
+    if( !registered_atoms.contains( atom ))
+        return;
+    foreach( EffectPair ep, loaded_effects )
+        ep.second->propertyNotify( c, atom );
+    }
+
+void EffectsHandlerImpl::registerPropertyType( long atom, bool reg )
+    {
+    if( reg )
+        ++registered_atoms[ atom ]; // initialized to 0 if not present yet
+    else
+        {
+        if( --registered_atoms[ atom ] == 0 )
+            registered_atoms.remove( atom );
+        }
+    }
+
 void EffectsHandlerImpl::activateWindow( EffectWindow* c )
     {
     if( Client* cl = dynamic_cast< Client* >( static_cast<EffectWindowImpl*>(c)->window()))
@@ -1024,6 +1043,42 @@ QRect EffectWindowImpl::contentsRect() const
     return QRect( toplevel->clientPos(), toplevel->clientSize());
     }
 
+QByteArray EffectWindowImpl::readProperty( long atom, long type, int format ) const
+    {
+    int len = 32768;
+    for(;;)
+        {
+        unsigned char* data;
+        Atom rtype;
+        int rformat;
+        unsigned long nitems, after;
+        if( XGetWindowProperty( QX11Info::display(), window()->window(),
+            atom, 0, len, False, AnyPropertyType,
+            &rtype, &rformat, &nitems, &after, &data ) == Success )
+            {
+            if( after > 0 )
+                {
+                XFree( data );
+                len *= 2;
+                continue;
+                }
+            if( long( rtype ) == type && rformat == format )
+                {
+                QByteArray ret( reinterpret_cast< const char* >( data ), nitems * ( format / 8 ));
+                XFree( data );
+                return ret;
+                }
+            else // wrong format, type or something
+                {
+                XFree( data );
+                return QByteArray();
+                }
+            }
+        else // XGetWindowProperty() failed
+            return QByteArray();
+        }
+    }
+
 bool EffectWindowImpl::isMovable() const
     {
     if( Client* c = dynamic_cast< Client* >( toplevel ))
diff --git a/effects.h b/effects.h
index 7151687805..a4aeecfbda 100644
--- a/effects.h
+++ b/effects.h
@@ -109,6 +109,7 @@ class EffectsHandlerImpl : public EffectsHandler
 
         virtual unsigned long xrenderBufferPicture();
         virtual void reconfigure();
+        virtual void registerPropertyType( long atom, bool reg );
 
         // internal (used by kwin core or compositing code)
         void startPaint();
@@ -131,6 +132,7 @@ class EffectsHandlerImpl : public EffectsHandler
             Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers );
         void grabbedKeyboardEvent( QKeyEvent* e );
         bool hasKeyboardGrab() const;
+        void propertyNotify( EffectWindow* c, long atom );
 
         bool loadEffect( const QString& name );
         void toggleEffect( const QString& name );
@@ -149,6 +151,7 @@ class EffectsHandlerImpl : public EffectsHandler
         Effect* fullscreen_effect;
         ToplevelList elevated_windows;
         QMultiMap< int, EffectPair > effect_order;
+        QHash< long, int > registered_atoms;
 };
 
 class EffectWindowImpl : public EffectWindow
@@ -192,6 +195,7 @@ class EffectWindowImpl : public EffectWindow
         virtual bool isUserResize() const;
         virtual QRect iconGeometry() const;
         virtual QRect contentsRect() const;
+        virtual QByteArray readProperty( long atom, long type, int format ) const;
 
         virtual bool isDesktop() const;
         virtual bool isDock() const;
diff --git a/events.cpp b/events.cpp
index ad1a181cfd..aa03c0c082 100644
--- a/events.cpp
+++ b/events.cpp
@@ -1724,6 +1724,8 @@ void Toplevel::propertyNotifyEvent( XPropertyEvent* e )
                 getWindowRole();
             break;
         }
+    if( effects )
+        static_cast< EffectsHandlerImpl* >( effects )->propertyNotify( effectWindow(), e->atom );
     }
 
 // ****************************************
diff --git a/lib/kwineffects.cpp b/lib/kwineffects.cpp
index 73e56bef1a..586ba29424 100644
--- a/lib/kwineffects.cpp
+++ b/lib/kwineffects.cpp
@@ -131,6 +131,10 @@ void Effect::grabbedKeyboardEvent( QKeyEvent* )
     {
     }
 
+void Effect::propertyNotify( EffectWindow* , long )
+    {
+    }
+
 void Effect::desktopChanged( int )
     {
     }
diff --git a/lib/kwineffects.h b/lib/kwineffects.h
index cb6b9975fe..9a6702a514 100644
--- a/lib/kwineffects.h
+++ b/lib/kwineffects.h
@@ -40,7 +40,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #define KWIN_EFFECT_API_MAKE_VERSION( major, minor ) (( major ) << 8 | ( minor )) 
 #define KWIN_EFFECT_API_VERSION_MAJOR 0
-#define KWIN_EFFECT_API_VERSION_MINOR 2
+#define KWIN_EFFECT_API_VERSION_MINOR 3
 #define KWIN_EFFECT_API_VERSION KWIN_EFFECT_API_MAKE_VERSION( \
     KWIN_EFFECT_API_VERSION_MAJOR, KWIN_EFFECT_API_VERSION_MINOR )
 
@@ -247,6 +247,14 @@ class KWIN_EXPORT Effect
         virtual void mouseChanged( const QPoint& pos, const QPoint& old,
             Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers );
         virtual void grabbedKeyboardEvent( QKeyEvent* e );
+        /**
+         Receives events registered for using EffectsHandler::registerPropertyType().
+         Use readProperty() to get the property data.
+         Note that the property may be already set on the window, so doing the same
+         processing from windowAdded() (e.g. simply calling propertyNotify() from it)
+         is usually needed.
+         */
+        virtual void propertyNotify( EffectWindow* w, long atom );
 
         virtual void tabBoxAdded( int mode );
         virtual void tabBoxClosed();
@@ -405,6 +413,14 @@ class KWIN_EXPORT EffectsHandler
         virtual unsigned long xrenderBufferPicture() = 0;
         virtual void reconfigure() = 0;
 
+        /**
+         Makes KWin core watch PropertyNotify events for the given atom,
+         or stops watching if reg is false (must be called the same number
+         of times as registering). Events are sent using Effect::propertyNotify().
+         Note that even events that haven't been registered for can be received.
+        */
+        virtual void registerPropertyType( long atom, bool reg ) = 0;
+
         /**
          * Paints given text onto screen, possibly in elided form
          * @param text
@@ -507,6 +523,7 @@ class KWIN_EXPORT EffectWindow
          */
         virtual QRect contentsRect() const = 0;
         bool hasDecoration() const;
+        virtual QByteArray readProperty( long atom, long type, int format ) const = 0;
 
         virtual QString caption() const = 0;
         virtual QPixmap icon() const = 0;