diff --git a/client.cpp b/client.cpp
index ec60bde9c7..0172a10c85 100644
--- a/client.cpp
+++ b/client.cpp
@@ -194,6 +194,10 @@ Client::Client(Workspace* ws)
     ready_for_painting = false; // wait for first damage or sync reply
 #endif
 
+    connect(this, SIGNAL(clientGeometryShapeChanged(KWin::Client*,QRect)), SIGNAL(geometryChanged()));
+    connect(this, SIGNAL(clientMaximizedStateChanged(KWin::Client*,KDecorationDefines::MaximizeMode)), SIGNAL(geometryChanged()));
+    connect(this, SIGNAL(clientStepUserMovedResized(KWin::Client*,QRect)), SIGNAL(geometryChanged()));
+
     // SELI TODO: Initialize xsizehints??
 }
 
diff --git a/shadow.cpp b/shadow.cpp
index 309a146b18..9e9179a608 100644
--- a/shadow.cpp
+++ b/shadow.cpp
@@ -31,7 +31,9 @@ namespace KWin
 
 Shadow::Shadow(Toplevel *toplevel)
     : m_topLevel(toplevel)
+    , m_cachedSize(toplevel->geometry().size())
 {
+    connect(m_topLevel, SIGNAL(geometryChanged()), SLOT(geometryChanged()));
 }
 
 Shadow::~Shadow()
@@ -99,14 +101,18 @@ bool Shadow::init(const QVector< long > &data)
     m_rightOffset = data[ShadowElementsCount+1];
     m_bottomOffset = data[ShadowElementsCount+2];
     m_leftOffset = data[ShadowElementsCount+3];
-    // prepare shadow region
+    updateShadowRegion();
+    buildQuads();
+    return true;
+}
+
+void Shadow::updateShadowRegion()
+{
     const QRect topRect(0, - m_topOffset, m_topLevel->width(), m_topOffset);
     const QRect rightRect(m_topLevel->width(), - m_topOffset, m_rightOffset, m_topLevel->height() + m_topOffset + m_bottomOffset);
     const QRect bottomRect(0, m_topLevel->height(), m_topLevel->width(), m_bottomOffset);
     const QRect leftRect(- m_leftOffset, - m_topOffset, m_leftOffset, m_topLevel->height() + m_topOffset + m_bottomOffset);
     m_shadowRegion = QRegion(topRect).united(rightRect).united(bottomRect).united(leftRect);
-    buildQuads();
-    return true;
 }
 
 void Shadow::buildQuads()
@@ -184,6 +190,16 @@ bool Shadow::updateShadow()
 void Shadow::setToplevel(Toplevel *topLevel)
 {
     m_topLevel = topLevel;
+    connect(m_topLevel, SIGNAL(geometryChanged()), SLOT(geometryChanged()));
+}
+void Shadow::geometryChanged()
+{
+    if (m_cachedSize == m_topLevel->geometry().size()) {
+        return;
+    }
+    m_cachedSize = m_topLevel->geometry().size();
+    updateShadowRegion();
+    buildQuads();
 }
 
 } // namespace
diff --git a/shadow.h b/shadow.h
index ee6dec35dc..7127db95ae 100644
--- a/shadow.h
+++ b/shadow.h
@@ -92,6 +92,9 @@ public:
      **/
     void setToplevel(Toplevel *toplevel);
 
+public Q_SLOTS:
+    void geometryChanged();
+
 protected:
     Shadow(Toplevel *toplevel);
     enum ShadowElements {
@@ -121,6 +124,7 @@ protected:
         return m_leftOffset;
     };
     virtual void buildQuads();
+    void updateShadowRegion();
 
 private:
     static QVector<long> readX11ShadowProperty(WId id);
@@ -136,6 +140,7 @@ private:
     // caches
     QRegion m_shadowRegion;
     WindowQuadList m_shadowQuads;
+    QSize m_cachedSize;
 };
 
 }
diff --git a/toplevel.h b/toplevel.h
index 49ac824b71..15a9aa361a 100644
--- a/toplevel.h
+++ b/toplevel.h
@@ -162,6 +162,7 @@ signals:
     void opacityChanged(KWin::Toplevel* toplevel, qreal oldOpacity);
     void damaged(KWin::Toplevel* toplevel, const QRect& damage);
     void propertyNotify(KWin::Toplevel* toplevel, long a);
+    void geometryChanged();
 
 protected:
     virtual ~Toplevel();
diff --git a/unmanaged.cpp b/unmanaged.cpp
index 7c36451b49..32908aabd2 100644
--- a/unmanaged.cpp
+++ b/unmanaged.cpp
@@ -32,6 +32,7 @@ namespace KWin
 Unmanaged::Unmanaged(Workspace* ws)
     : Toplevel(ws)
 {
+    connect(this, SIGNAL(unmanagedGeometryShapeChanged(KWin::Unmanaged*,QRect)), SIGNAL(geometryChanged()));
 }
 
 Unmanaged::~Unmanaged()