diff --git a/kcmkwin/kwindecoration/kwindecoration.cpp b/kcmkwin/kwindecoration/kwindecoration.cpp
index 34d9b48261..1f7a20969b 100644
--- a/kcmkwin/kwindecoration/kwindecoration.cpp
+++ b/kcmkwin/kwindecoration/kwindecoration.cpp
@@ -121,6 +121,7 @@ KWinDecorationModule::KWinDecorationModule(QWidget* parent, const QVariantList &
     connect(m_ui->decorationList->verticalScrollBar(), SIGNAL(valueChanged(int)), SLOT(updateViewPosition(int)));
 
     m_ui->decorationList->installEventFilter(this);
+    m_ui->decorationList->viewport()->installEventFilter(this);
 
     KAboutData *about =
         new KAboutData(I18N_NOOP("kcmkwindecoration"), 0,
@@ -404,6 +405,10 @@ bool KWinDecorationModule::eventFilter(QObject *o, QEvent *e)
                 return true;
             }
         }
+    } else if (m_ui->decorationList->viewport()) {
+        if (e->type() == QEvent::Wheel) {
+            return static_cast<QWheelEvent*>(e)->orientation() == Qt::Horizontal;
+        }
     }
     return KCModule::eventFilter(o, e);
 }