diff --git a/compositingprefs.cpp b/compositingprefs.cpp
index 84bdaeca89..fe76dc8e7d 100644
--- a/compositingprefs.cpp
+++ b/compositingprefs.cpp
@@ -107,6 +107,28 @@ QString CompositingPrefs::compositingNotPossibleReason()
 #endif
     }
 
+// This function checks selected compositing setup and returns false if it should not
+// be used even if explicitly configured (unless checks are overriden).
+// More checks like broken XRender setups etc. should be added here.
+bool CompositingPrefs::validateSetup( CompositingType compositingType ) const
+    {
+    switch( compositingType )
+        {
+        case NoCompositing:
+            return false;
+        case OpenGLCompositing:
+            if( mDriver == "software" )
+                {
+                kDebug( 1212 ) << "Software GL renderer detected, forcing compositing off.";
+                return false;
+                }
+            return true; // allow
+        case XRenderCompositing:
+            return true; // xrender - always allow?
+        }
+    abort();
+    }
+
 void CompositingPrefs::detect()
     {
     if( !compositingPossible())
@@ -240,6 +262,12 @@ void CompositingPrefs::detectDriverAndVersion()
         mDriver = "radeon";
         mVersion = Version( mGLRenderer.split(" ")[ 3 ] );
         }
+    else if( mGLRenderer == "Software Rasterizer" )
+        {
+        mDriver = "software";
+        QStringList words = mGLVersion.split(" ");
+        mVersion = Version( words[ words.count() - 1 ] );
+        }
     else
         {
         mDriver = "unknown";
diff --git a/compositingprefs.h b/compositingprefs.h
index 73155a0ee9..c0722bb8a2 100644
--- a/compositingprefs.h
+++ b/compositingprefs.h
@@ -25,6 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QStringList>
 
 #include "kwinglutils.h"
+#include "kwinglobals.h"
 
 
 namespace KWin
@@ -52,6 +53,7 @@ public:
 
     static bool compositingPossible();
     static QString compositingNotPossibleReason();
+    bool validateSetup( CompositingType compositingType ) const;
     bool enableCompositing() const;
     bool enableVSync() const  { return mEnableVSync; }
     bool enableDirectRendering() const  { return mEnableDirectRendering; }
diff --git a/options.cpp b/options.cpp
index 867aee124f..c501c882e3 100644
--- a/options.cpp
+++ b/options.cpp
@@ -239,6 +239,9 @@ void Options::reloadCompositingSettings(const CompositingPrefs& prefs)
     
     unredirectFullscreen = config.readEntry( "UnredirectFullscreen", true );
     animationSpeed = qBound( 0, config.readEntry( "AnimationSpeed", 3 ), 6 );
+    
+    if( !disableCompositingChecks && !prefs.validateSetup( compositingMode ))
+        useCompositing = false;
     }