diff --git a/libkwineffects/CMakeLists.txt b/libkwineffects/CMakeLists.txt
index 16c463d4a4..c906372481 100644
--- a/libkwineffects/CMakeLists.txt
+++ b/libkwineffects/CMakeLists.txt
@@ -2,7 +2,6 @@
 
 ###  effects lib  ###
 set(kwin_EFFECTSLIB_SRCS
-    kwinglobals.cpp
     kwineffects.cpp
     anidata.cpp
     kwinanimationeffect.cpp
@@ -21,9 +20,6 @@ set(kwineffects_KDE_LIBS
 
 set(kwineffects_XLIB_LIBS
     ${X11_X11_LIB}
-    ${X11_Xext_LIB}
-    ${X11_Xrandr_LIB}
-    ${X11_Xdamage_LIB}
 )
 
 set(kwineffects_XCB_LIBS
diff --git a/libkwineffects/kwinglobals.cpp b/libkwineffects/kwinglobals.cpp
deleted file mode 100644
index bd7d2d23db..0000000000
--- a/libkwineffects/kwinglobals.cpp
+++ /dev/null
@@ -1,57 +0,0 @@
-/********************************************************************
- KWin - the KDE window manager
- This file is part of the KDE project.
-
-Copyright (C) 2006 Lubos Lunak <l.lunak@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 "kwinglobals.h"
-
-#include <config-X11.h>
-
-#include <assert.h>
-
-#include <X11/Xlib.h>
-#include <X11/extensions/shape.h>
-
-#include <X11/extensions/Xdamage.h>
-#include <X11/extensions/Xrandr.h>
-#ifdef HAVE_XSYNC
-#include <X11/extensions/sync.h>
-#endif
-
-namespace KWin
-{
-
-void Extensions::init()
-{
-    static bool initPerformed = false;
-    if (initPerformed) {
-        return;
-    }
-    //  it seems like no events are delivered to XLib when the extension is not queried
-    int event_base, error_base;
-    XShapeQueryExtension(display(), &event_base, &error_base);
-    XRRQueryExtension(display(), &event_base, &error_base);
-    XDamageQueryExtension(display(), &event_base, &error_base);
-#ifdef HAVE_XSYNC
-    XSyncQueryExtension(display(), &event_base, &error_base);
-#endif
-    initPerformed = true;
-}
-
-} // namespace
-
diff --git a/libkwineffects/kwinglobals.h b/libkwineffects/kwinglobals.h
index 9e214498dc..b16b10eb7b 100644
--- a/libkwineffects/kwinglobals.h
+++ b/libkwineffects/kwinglobals.h
@@ -183,14 +183,6 @@ KWIN_EXPORT int displayHeight()
     return screen ? screen->height_in_pixels : 0;
 }
 
-/** @internal */
-// TODO: QT5: remove
-class KWIN_EXPORT Extensions
-{
-public:
-    static void init();
-};
-
 } // namespace
 
 #define KWIN_SINGLETON_VARIABLE(ClassName, variableName) \
diff --git a/workspace.cpp b/workspace.cpp
index 9be8d598da..9f5ebdf718 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -172,7 +172,6 @@ Workspace::Workspace(bool restore)
     _self = this;
 
     // first initialize the extensions
-    Extensions::init();
     Xcb::Extensions::self();
 
     // start the cursor support