diff --git a/effects/flipswitch/flipswitch.cpp b/effects/flipswitch/flipswitch.cpp
index 69a33822cb..01062a9993 100644
--- a/effects/flipswitch/flipswitch.cpp
+++ b/effects/flipswitch/flipswitch.cpp
@@ -39,7 +39,8 @@ namespace KWin
 {
 
 FlipSwitchEffect::FlipSwitchEffect()
-    : m_currentAnimationShape(QTimeLine::EaseInOutCurve)
+    : m_selectedWindow(nullptr)
+    , m_currentAnimationShape(QTimeLine::EaseInOutCurve)
     , m_active(false)
     , m_start(false)
     , m_stop(false)