diff --git a/effects.cpp b/effects.cpp
index 3577535bd1..a4ad2010b5 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -488,6 +488,7 @@ bool EffectsHandlerImpl::decorationSupportsBlurBehind() const
 void EffectsHandlerImpl::startPaint()
 {
     m_activeEffects.clear();
+    m_activeEffects.reserve(loaded_effects.count());
     for(QVector< KWin::EffectPair >::const_iterator it = loaded_effects.constBegin(); it != loaded_effects.constEnd(); ++it) {
         if (it->second->isActive()) {
             m_activeEffects << it->second;
@@ -1552,6 +1553,7 @@ void EffectsHandlerImpl::effectsChanged()
 //        kDebug(1212) << effect.first;
         loaded_effects.append(effect);
     }
+    m_activeEffects.reserve(loaded_effects.count());
 }
 
 QStringList EffectsHandlerImpl::activeEffects() const
diff --git a/effects.h b/effects.h
index 1850089499..43f2c14642 100644
--- a/effects.h
+++ b/effects.h
@@ -253,9 +253,9 @@ private Q_SLOTS:
     void slotEffectsQueried();
 
 private:
-    QList< Effect* > m_activeEffects;
-    typedef QList< Effect*> EffectsList;
+    typedef QVector< Effect*> EffectsList;
     typedef EffectsList::const_iterator EffectsIterator;
+    EffectsList m_activeEffects;
     EffectsIterator m_currentDrawWindowIterator;
     EffectsIterator m_currentPaintWindowIterator;
     EffectsIterator m_currentPaintEffectFrameIterator;