diff --git a/events.cpp b/events.cpp
--- a/events.cpp
+++ b/events.cpp
@@ -63,7 +63,6 @@
 #endif
 
 #include "composite.h"
-#include "killwindow.h"
 #include "x11eventfilter.h"
 
 #include "wayland_server.h"
@@ -253,12 +252,6 @@
             && (eventType == XCB_KEY_PRESS || eventType == XCB_KEY_RELEASE))
         return false; // let Qt process it, it'll be intercepted again in eventFilter()
 
-    if (!m_windowKiller.isNull() && m_windowKiller->isActive() && m_windowKiller->isResponsibleForEvent(eventType)) {
-        m_windowKiller->processEvent(e);
-        // filter out the event
-        return true;
-    }
-
     if (eventType == XCB_PROPERTY_NOTIFY || eventType == XCB_CLIENT_MESSAGE) {
         NET::Properties dirtyProtocols;
         NET::Properties2 dirtyProtocols2;
diff --git a/killwindow.h b/killwindow.h
--- a/killwindow.h
+++ b/killwindow.h
@@ -23,12 +23,14 @@
 #ifndef KWIN_KILLWINDOW_H
 #define KWIN_KILLWINDOW_H
 
+#include "x11eventfilter.h"
+
 #include <xcb/xcb.h>
 
 namespace KWin
 {
 
-class KillWindow
+class KillWindow : public X11EventFilter
 {
 public:
 
@@ -39,9 +41,10 @@
     bool isActive() const {
         return m_active;
     }
-    bool isResponsibleForEvent(int eventType) const;
     void processEvent(xcb_generic_event_t *event);
 
+    bool event(xcb_generic_event_t *event) override;
+
 private:
     xcb_cursor_t createCursor();
     void release();
diff --git a/killwindow.cpp b/killwindow.cpp
--- a/killwindow.cpp
+++ b/killwindow.cpp
@@ -35,7 +35,17 @@
 {
 
 KillWindow::KillWindow()
-    : m_active(false)
+    : X11EventFilter(QVector<int>{XCB_BUTTON_PRESS,
+                                  XCB_BUTTON_RELEASE,
+                                  XCB_MOTION_NOTIFY,
+                                  XCB_ENTER_NOTIFY,
+                                  XCB_LEAVE_NOTIFY,
+                                  XCB_KEY_PRESS,
+                                  XCB_KEY_RELEASE,
+                                  XCB_FOCUS_IN,
+                                  XCB_FOCUS_OUT
+    })
+    , m_active(false)
 {
 }
 
@@ -89,24 +99,6 @@
     return cursor;
 }
 
-bool KillWindow::isResponsibleForEvent(int eventType) const
-{
-    switch (eventType) {
-        case XCB_BUTTON_PRESS:
-        case XCB_BUTTON_RELEASE:
-        case XCB_MOTION_NOTIFY:
-        case XCB_ENTER_NOTIFY:
-        case XCB_LEAVE_NOTIFY:
-        case XCB_KEY_PRESS:
-        case XCB_KEY_RELEASE:
-        case XCB_FOCUS_IN:
-        case XCB_FOCUS_OUT:
-            return true;
-        default:
-            return false;
-    }
-}
-
 void KillWindow::processEvent(xcb_generic_event_t *event)
 {
     if (event->response_type == XCB_BUTTON_RELEASE) {
@@ -118,6 +110,16 @@
     }
 }
 
+bool KillWindow::event(xcb_generic_event_t *event)
+{
+    if (!m_active) {
+        return false;
+    }
+    processEvent(event);
+
+    return true;
+}
+
 void KillWindow::handleButtonRelease(xcb_button_t button, xcb_window_t window)
 {
     if (button == XCB_BUTTON_INDEX_3) {