diff --git a/bridge.cpp b/bridge.cpp
index e59cfe619c..0716e65d58 100644
--- a/bridge.cpp
+++ b/bridge.cpp
@@ -176,18 +176,18 @@ QRegion Bridge::unobscuredRegion( const QRegion& r ) const
                 continue;
             }
         /* the clients all have their mask-regions in local coords
-	   so we have to translate them to a shared coord system
-	   we choose ours */
-	int dx = stacking_order[ pos ]->x() - c->x();
-	int dy = stacking_order[ pos ]->y() - c->y();
-	QRegion creg = stacking_order[ pos ]->mask();
-	creg.translate(dx, dy);
-	reg -= creg;
-	if (reg.isEmpty())
+           so we have to translate them to a shared coord system
+           we choose ours */
+        int dx = stacking_order[ pos ]->x() - c->x();
+        int dy = stacking_order[ pos ]->y() - c->y();
+        QRegion creg = stacking_order[ pos ]->mask();
+        creg.translate(dx, dy);
+        reg -= creg;
+        if (reg.isEmpty())
             {
-	    // early out, we are completely obscured
-	    break;
-	    }
+            // early out, we are completely obscured
+            break;
+            }
         }
     return reg;
     }
diff --git a/kcmkwin/kwindecoration/preview.cpp b/kcmkwin/kwindecoration/preview.cpp
index cf74e9b3fa..4c6e4becf8 100644
--- a/kcmkwin/kwindecoration/preview.cpp
+++ b/kcmkwin/kwindecoration/preview.cpp
@@ -66,7 +66,7 @@ KDecorationPreview::~KDecorationPreview()
         {
         delete deco[i];
         delete bridge[i];
-	}
+        }
     delete options;
     }
 
@@ -128,7 +128,7 @@ void KDecorationPreview::positionPreviews()
 
     titleBarHeight = qMin( int( titleBarHeight * .9 ), 30 );
     xoffset = qMin( qMax( 10, QApplication::isRightToLeft()
-			    ? leftBorder : rightBorder ), 30 );
+                            ? leftBorder : rightBorder ), 30 );
 
     // Resize the active window
     size = QSize( width() - xoffset, height() - titleBarHeight )
@@ -167,7 +167,7 @@ void KDecorationPreview::setPreviewMask( const QRegion& reg, int mode, bool acti
             xrects[ i ].height = rects[ i ].height();
             }
         XShapeCombineRectangles( QX11Info::display(), widget->winId(), ShapeBounding, 0, 0,
-	    xrects, rects.count(), ShapeSet, mode );
+            xrects, rects.count(), ShapeSet, mode );
         delete[] xrects;
         }
     if( active )
diff --git a/kcmkwin/kwindecoration/preview.h b/kcmkwin/kwindecoration/preview.h
index ee5b03dbca..27dbf7e92d 100644
--- a/kcmkwin/kwindecoration/preview.h
+++ b/kcmkwin/kwindecoration/preview.h
@@ -70,11 +70,11 @@ class KDecorationPreviewBridge
     {
     public:
         KDecorationPreviewBridge( KDecorationPreview* preview, bool active );
-    	virtual bool isActive() const;
-	virtual bool isCloseable() const;
-	virtual bool isMaximizable() const;
-	virtual MaximizeMode maximizeMode() const;
-	virtual bool isMinimizable() const;
+        virtual bool isActive() const;
+        virtual bool isCloseable() const;
+        virtual bool isMaximizable() const;
+        virtual MaximizeMode maximizeMode() const;
+        virtual bool isMinimizable() const;
         virtual bool providesContextHelp() const;
         virtual int desktop() const;
         virtual bool isModal() const;
@@ -86,21 +86,21 @@ class KDecorationPreviewBridge
         virtual bool isMovable() const;
         virtual bool isResizable() const;
         virtual NET::WindowType windowType( unsigned long supported_types ) const;
-	virtual QIcon icon() const;
-	virtual QString caption() const;
-	virtual void processMousePressEvent( QMouseEvent* );
-	virtual void showWindowMenu( const QRect &);
-	virtual void showWindowMenu( const QPoint & );
-	virtual void performWindowOperation( WindowOperation );
+        virtual QIcon icon() const;
+        virtual QString caption() const;
+        virtual void processMousePressEvent( QMouseEvent* );
+        virtual void showWindowMenu( const QRect &);
+        virtual void showWindowMenu( const QPoint & );
+        virtual void performWindowOperation( WindowOperation );
         virtual void setMask( const QRegion&, int );
         virtual bool isPreview() const;
         virtual QRect geometry() const;
         virtual QRect iconGeometry() const;
         virtual QRegion unobscuredRegion( const QRegion& r ) const;
         virtual WId windowId() const;
-	virtual void closeWindow();
-	virtual void maximize( MaximizeMode mode );
-	virtual void minimize();
+        virtual void closeWindow();
+        virtual void maximize( MaximizeMode mode );
+        virtual void minimize();
         virtual void showContextHelp();
         virtual void setDesktop( int desktop );
         virtual void titlebarDblClickOperation();