diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -418,7 +418,6 @@
    options.cpp
    outline.cpp
    events.cpp
-   killwindow.cpp
    geometrytip.cpp
    screens.cpp
    outputscreens.cpp
diff --git a/killwindow.h b/killwindow.h
deleted file mode 100644
--- a/killwindow.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/********************************************************************
- KWin - the KDE window manager
- This file is part of the KDE project.
-
-Copyright (C) 1999, 2000 Matthias Ettrich <ettrich@kde.org>
-Copyright (C) 2003 Lubos Lunak <l.lunak@kde.org>
-Copyright (C) 2012 Martin Gräßlin <mgraesslin@kde.org>
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*********************************************************************/
-
-#ifndef KWIN_KILLWINDOW_H
-#define KWIN_KILLWINDOW_H
-
-namespace KWin
-{
-
-class KillWindow
-{
-public:
-
-    KillWindow();
-    ~KillWindow();
-
-    void start();
-};
-
-} // namespace
-
-#endif
diff --git a/killwindow.cpp b/killwindow.cpp
deleted file mode 100644
--- a/killwindow.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-/********************************************************************
- KWin - the KDE window manager
- This file is part of the KDE project.
-
-Copyright (C) 1999, 2000 Matthias Ettrich <ettrich@kde.org>
-Copyright (C) 2003 Lubos Lunak <l.lunak@kde.org>
-Copyright (C) 2012 Martin Gräßlin <mgraesslin@kde.org>
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*********************************************************************/
-#include "killwindow.h"
-#include "abstract_client.h"
-#include "main.h"
-#include "platform.h"
-#include "osd.h"
-#include "unmanaged.h"
-
-#include <KLocalizedString>
-
-namespace KWin
-{
-
-KillWindow::KillWindow()
-{
-}
-
-KillWindow::~KillWindow()
-{
-}
-
-void KillWindow::start()
-{
-    OSD::show(i18n("Select window to force close with left click or enter.\nEscape or right click to cancel."),
-              QStringLiteral("window-close"));
-    kwinApp()->platform()->startInteractiveWindowSelection(
-        [] (KWin::Toplevel *t) {
-            OSD::hide();
-            if (!t) {
-                return;
-            }
-            if (AbstractClient *c = qobject_cast<AbstractClient*>(t)) {
-                c->killWindow();
-            } else if (Unmanaged *u = qobject_cast<Unmanaged*>(t)) {
-                xcb_kill_client(connection(), u->window());
-            }
-        }, QByteArrayLiteral("pirate")
-    );
-}
-
-} // namespace
diff --git a/useractions.cpp b/useractions.cpp
--- a/useractions.cpp
+++ b/useractions.cpp
@@ -43,6 +43,8 @@
 #include "shell_client.h"
 #include "virtualdesktops.h"
 #include "scripting/scripting.h"
+#include "osd.h"
+#include "unmanaged.h"
 
 #ifdef KWIN_BUILD_ACTIVITIES
 #include "activities.h"
@@ -66,7 +68,6 @@
 #include <QWidgetAction>
 #include <kauthorized.h>
 
-#include "killwindow.h"
 #ifdef KWIN_BUILD_TABBOX
 #include "tabbox.h"
 #endif
@@ -1665,10 +1666,21 @@
  */
 void Workspace::slotKillWindow()
 {
-    if (m_windowKiller.isNull()) {
-        m_windowKiller.reset(new KillWindow());
-    }
-    m_windowKiller->start();
+    OSD::show(i18n("Select window to force close with left click or enter.\nEscape or right click to cancel."),
+              QStringLiteral("window-close"));
+    kwinApp()->platform()->startInteractiveWindowSelection(
+        [] (KWin::Toplevel *t) {
+            OSD::hide();
+            if (!t) {
+                return;
+            }
+            if (AbstractClient *c = qobject_cast<AbstractClient*>(t)) {
+                c->killWindow();
+            } else if (Unmanaged *u = qobject_cast<Unmanaged*>(t)) {
+                xcb_kill_client(connection(), u->window());
+            }
+        }, QByteArrayLiteral("pirate")
+    );
 }
 
 /*!
diff --git a/workspace.h b/workspace.h
--- a/workspace.h
+++ b/workspace.h
@@ -54,7 +54,6 @@
 
 class AbstractClient;
 class Client;
-class KillWindow;
 class ShortcutDialog;
 class UserActionsMenu;
 class Compositor;
@@ -621,8 +620,6 @@
     QScopedPointer<Xcb::Window> m_nullFocus;
     friend class StackingUpdatesBlocker;
 
-    QScopedPointer<KillWindow> m_windowKiller;
-
     QList<X11EventFilter *> m_eventFilters;
     QList<X11EventFilter *> m_genericEventFilters;
     QScopedPointer<X11EventFilter> m_movingClientFilter;
diff --git a/workspace.cpp b/workspace.cpp
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -39,7 +39,6 @@
 #include "input.h"
 #include "logind.h"
 #include "moving_client_x11_filter.h"
-#include "killwindow.h"
 #include "netinfo.h"
 #include "outline.h"
 #include "placement.h"