diff --git a/data/update_default_rules.cpp b/data/update_default_rules.cpp
index 503556a12b..172cbaf1e9 100644
--- a/data/update_default_rules.cpp
+++ b/data/update_default_rules.cpp
@@ -9,11 +9,13 @@
 
 // read additional window rules and add them to kwinrulesrc
 
+#include <KConfig>
+#include <KConfigGroup>
+#include <QCoreApplication>
+#include <QDBusConnection>
+#include <QDBusMessage>
 #include <QDebug>
 #include <QStandardPaths>
-#include <QtDBus>
-#include <kconfig.h>
-#include <kconfiggroup.h>
 
 int main(int argc, char *argv[])
 {
diff --git a/src/activities.h b/src/activities.h
index e1fecd455b..ee61f4ef75 100644
--- a/src/activities.h
+++ b/src/activities.h
@@ -8,10 +8,9 @@
 */
 #pragma once
 
-#include "effect/globals.h"
-
 #include <QObject>
 #include <QStringList>
+#include <kwin_export.h>
 
 #include <PlasmaActivities/Controller>
 
diff --git a/src/appmenu.h b/src/appmenu.h
index 54e481225c..55bdc149ae 100644
--- a/src/appmenu.h
+++ b/src/appmenu.h
@@ -9,8 +9,6 @@
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #pragma once
-// KWin
-#include "effect/globals.h"
 // Qt
 #include <QObject>
 // xcb
diff --git a/src/backends/drm/drm_abstract_output.cpp b/src/backends/drm/drm_abstract_output.cpp
index 78aa5c6085..2d27b707d9 100644
--- a/src/backends/drm/drm_abstract_output.cpp
+++ b/src/backends/drm/drm_abstract_output.cpp
@@ -8,7 +8,6 @@
 */
 #include "drm_abstract_output.h"
 #include "core/renderbackend.h"
-#include "core/renderloop_p.h"
 #include "drm_backend.h"
 #include "drm_gpu.h"
 #include "drm_layer.h"
diff --git a/src/backends/drm/drm_buffer.cpp b/src/backends/drm/drm_buffer.cpp
index c2e3ec2043..1f246463db 100644
--- a/src/backends/drm/drm_buffer.cpp
+++ b/src/backends/drm/drm_buffer.cpp
@@ -11,7 +11,6 @@
 
 #include "core/graphicsbuffer.h"
 #include "drm_gpu.h"
-#include "drm_logging.h"
 
 // system
 #include <sys/mman.h>
@@ -19,8 +18,6 @@
 #include <linux/dma-buf.h>
 #include <linux/sync_file.h>
 #endif
-// c++
-#include <cerrno>
 // drm
 #include <drm_fourcc.h>
 #include <sys/ioctl.h>
diff --git a/src/backends/drm/drm_crtc.cpp b/src/backends/drm/drm_crtc.cpp
index 7ec300c1c5..c7c9168682 100644
--- a/src/backends/drm/drm_crtc.cpp
+++ b/src/backends/drm/drm_crtc.cpp
@@ -11,10 +11,8 @@
 #include "drm_buffer.h"
 #include "drm_commit.h"
 #include "drm_gpu.h"
-#include "drm_logging.h"
 #include "drm_output.h"
 #include "drm_pointer.h"
-#include <cerrno>
 
 namespace KWin
 {
diff --git a/src/backends/drm/drm_egl_backend.cpp b/src/backends/drm/drm_egl_backend.cpp
index 72707e37cd..cfb7a482a0 100644
--- a/src/backends/drm/drm_egl_backend.cpp
+++ b/src/backends/drm/drm_egl_backend.cpp
@@ -18,10 +18,8 @@
 #include "drm_output.h"
 #include "drm_pipeline.h"
 #include "drm_virtual_egl_layer.h"
-#include "opengl/eglutils_p.h"
 // system
 #include <drm_fourcc.h>
-#include <errno.h>
 #include <gbm.h>
 #include <unistd.h>
 
diff --git a/src/backends/drm/icc_shader.cpp b/src/backends/drm/icc_shader.cpp
index e8b00070fc..ea3e0a2a58 100644
--- a/src/backends/drm/icc_shader.cpp
+++ b/src/backends/drm/icc_shader.cpp
@@ -11,7 +11,6 @@
 #include "opengl/gllut3D.h"
 #include "opengl/glshader.h"
 #include "opengl/glshadermanager.h"
-#include "opengl/gltexture.h"
 
 namespace KWin
 {
diff --git a/src/compositor.h b/src/compositor.h
index 7957e6d536..2f0ea7c1a6 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -9,9 +9,10 @@
 */
 #pragma once
 
-#include "effect/globals.h"
+#include <kwin_export.h>
 #include <xcb/xcb.h>
 
+#include <QHash>
 #include <QObject>
 #include <QRegion>
 #include <QTimer>
diff --git a/src/compositor_wayland.h b/src/compositor_wayland.h
index 0d0529f5a6..4d501825d8 100644
--- a/src/compositor_wayland.h
+++ b/src/compositor_wayland.h
@@ -11,6 +11,7 @@
 #pragma once
 
 #include "compositor.h"
+#include "effect/globals.h"
 
 namespace KWin
 {
diff --git a/src/compositor_x11.h b/src/compositor_x11.h
index be396e4787..8c1a91e8e2 100644
--- a/src/compositor_x11.h
+++ b/src/compositor_x11.h
@@ -11,6 +11,7 @@
 #pragma once
 
 #include "compositor.h"
+#include <QSet>
 
 namespace KWin
 {
diff --git a/src/decorations/decorationbridge.h b/src/decorations/decorationbridge.h
index cd37716a1a..b52f233da9 100644
--- a/src/decorations/decorationbridge.h
+++ b/src/decorations/decorationbridge.h
@@ -8,14 +8,11 @@
 */
 #pragma once
 
-#include "effect/globals.h"
-
+#include "kwin_export.h"
 #include <KDecoration2/Private/DecorationBridge>
-
 #include <QObject>
 
 class KPluginFactory;
-
 namespace KDecoration2
 {
 class DecorationSettings;
diff --git a/src/decorations/decorationpalette.cpp b/src/decorations/decorationpalette.cpp
index d659269fd9..3fab1b907b 100644
--- a/src/decorations/decorationpalette.cpp
+++ b/src/decorations/decorationpalette.cpp
@@ -11,7 +11,6 @@
 */
 
 #include "decorationpalette.h"
-#include "decorations_logging.h"
 
 #include <KConfigGroup>
 
diff --git a/src/effect/anidata.cpp b/src/effect/anidata.cpp
index 77e1c27d8b..c8e34a543b 100644
--- a/src/effect/anidata.cpp
+++ b/src/effect/anidata.cpp
@@ -11,8 +11,6 @@
 #include "effect/anidata_p.h"
 #include "effect/effecthandler.h"
 
-#include "logging_p.h"
-
 namespace KWin
 {
 
diff --git a/src/effect/animationeffect.cpp b/src/effect/animationeffect.cpp
index bfd18ba639..4305c974f2 100644
--- a/src/effect/animationeffect.cpp
+++ b/src/effect/animationeffect.cpp
@@ -11,7 +11,8 @@
 #include "effect/animationeffect.h"
 #include "effect/anidata_p.h"
 #include "effect/effecthandler.h"
-#include "opengl/glutils.h"
+#include "opengl/glshader.h"
+#include "opengl/glshadermanager.h"
 
 #include <QDateTime>
 #include <QTimer>
diff --git a/src/effect/effecthandler.cpp b/src/effect/effecthandler.cpp
index 38b6559b48..aa1a359474 100644
--- a/src/effect/effecthandler.cpp
+++ b/src/effect/effecthandler.cpp
@@ -16,7 +16,6 @@
 #include "compositor.h"
 #include "core/output.h"
 #include "core/renderbackend.h"
-#include "core/renderlayer.h"
 #include "core/rendertarget.h"
 #include "core/renderviewport.h"
 #include "decorations/decorationbridge.h"
@@ -28,7 +27,9 @@
 #include "inputmethod.h"
 #include "inputpanelv1window.h"
 #include "keyboard_input.h"
-#include "opengl/glutils.h"
+#include "opengl/glshader.h"
+#include "opengl/glshadermanager.h"
+#include "opengl/gltexture.h"
 #include "osd.h"
 #include "pointer_input.h"
 #include "scene/itemrenderer.h"
@@ -65,8 +66,6 @@
 #include <QWindow>
 #include <QtMath>
 
-#include <optional>
-
 namespace KWin
 {
 
diff --git a/src/effect/effecthandler.h b/src/effect/effecthandler.h
index 76ac1b697e..f3a2c1ef14 100644
--- a/src/effect/effecthandler.h
+++ b/src/effect/effecthandler.h
@@ -29,11 +29,7 @@
 
 #include <netwm.h>
 
-#include <climits>
-#include <cmath>
 #include <functional>
-#include <optional>
-#include <span>
 
 class KConfigGroup;
 class QFont;
diff --git a/src/kcms/compositing/kwincompositingdata.h b/src/kcms/compositing/kwincompositingdata.h
index 1d2b7403df..416b85a535 100644
--- a/src/kcms/compositing/kwincompositingdata.h
+++ b/src/kcms/compositing/kwincompositingdata.h
@@ -11,7 +11,7 @@
 
 #include <QObject>
 
-#include "kcmoduledata.h"
+#include <KCModuleData>
 
 class KWinCompositingSetting;
 
diff --git a/src/kcms/decoration/decorationmodel.cpp b/src/kcms/decoration/decorationmodel.cpp
index 9c10adc16a..4d2aaa52dd 100644
--- a/src/kcms/decoration/decorationmodel.cpp
+++ b/src/kcms/decoration/decorationmodel.cpp
@@ -4,6 +4,7 @@
     SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
 */
 #include "decorationmodel.h"
+#include "utils.h"
 // KDecoration2
 #include <KDecoration2/Decoration>
 #include <KDecoration2/DecorationSettings>
diff --git a/src/kcms/decoration/decorationmodel.h b/src/kcms/decoration/decorationmodel.h
index a52e4c7807..6b3e8be9c2 100644
--- a/src/kcms/decoration/decorationmodel.h
+++ b/src/kcms/decoration/decorationmodel.h
@@ -5,8 +5,6 @@
 */
 #pragma once
 
-#include "utils.h"
-
 #include <KDecoration2/DecorationThemeProvider>
 #include <QAbstractListModel>
 
diff --git a/src/kcms/decoration/kcm.cpp b/src/kcms/decoration/kcm.cpp
index c770d24243..ac9d5a2ef8 100644
--- a/src/kcms/decoration/kcm.cpp
+++ b/src/kcms/decoration/kcm.cpp
@@ -24,6 +24,7 @@
 
 #include "kwindecorationdata.h"
 #include "kwindecorationsettings.h"
+#include "utils.h"
 
 K_PLUGIN_FACTORY_WITH_JSON(KCMKWinDecorationFactory, "kcm_kwindecoration.json", registerPlugin<KCMKWinDecoration>(); registerPlugin<KWinDecorationData>();)
 
diff --git a/src/kcms/decoration/kcm.h b/src/kcms/decoration/kcm.h
index 65607438af..a30c127e36 100644
--- a/src/kcms/decoration/kcm.h
+++ b/src/kcms/decoration/kcm.h
@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include "utils.h"
-
 #include <KQuickManagedConfigModule>
 #include <QAbstractListModel>
 
diff --git a/src/kcms/options/mouse.cpp b/src/kcms/options/mouse.cpp
index 8756edb402..b4e55a6cb0 100644
--- a/src/kcms/options/mouse.cpp
+++ b/src/kcms/options/mouse.cpp
@@ -5,13 +5,11 @@
 */
 
 #include "mouse.h"
-
-#include <QtDBus>
-
-#include <cstdlib>
-
 #include "kwinoptions_settings.h"
 
+#include <QDBusConnection>
+#include <QDBusMessage>
+
 KWinMouseConfigForm::KWinMouseConfigForm(QWidget *parent)
     : QWidget(parent)
 {
diff --git a/src/kcms/scripts/module.cpp b/src/kcms/scripts/module.cpp
index fe91923a39..b63d0fc2f0 100644
--- a/src/kcms/scripts/module.cpp
+++ b/src/kcms/scripts/module.cpp
@@ -20,7 +20,6 @@
 #include <KPackage/PackageLoader>
 #include <KSharedConfig>
 
-#include "config-kwin.h"
 #include "kwinscriptsdata.h"
 
 Module::Module(QObject *parent, const KPluginMetaData &data)
diff --git a/src/kcms/tabbox/main.cpp b/src/kcms/tabbox/main.cpp
index 8beb5972e8..882c7221e0 100644
--- a/src/kcms/tabbox/main.cpp
+++ b/src/kcms/tabbox/main.cpp
@@ -36,7 +36,6 @@
 
 // own
 #include "kwinpluginssettings.h"
-#include "kwinswitcheffectsettings.h"
 #include "kwintabboxconfigform.h"
 #include "kwintabboxdata.h"
 #include "kwintabboxsettings.h"
diff --git a/src/kcms/tabbox/main.h b/src/kcms/tabbox/main.h
index a1a988469b..69e8b2c612 100644
--- a/src/kcms/tabbox/main.h
+++ b/src/kcms/tabbox/main.h
@@ -11,7 +11,6 @@
 
 #pragma once
 
-#include "tabbox/tabboxconfig.h"
 #include <kcmodule.h>
 #include <ksharedconfig.h>
 
diff --git a/src/scripting/scriptedeffect.cpp b/src/scripting/scriptedeffect.cpp
index 6e6a081185..d3f9aed305 100644
--- a/src/scripting/scriptedeffect.cpp
+++ b/src/scripting/scriptedeffect.cpp
@@ -9,8 +9,9 @@
 */
 
 #include "scriptedeffect.h"
+#include "opengl/glshader.h"
+#include "opengl/glshadermanager.h"
 #include "scripting_logging.h"
-#include "scriptingutils.h"
 #include "workspace_wrapper.h"
 
 #include "core/output.h"
@@ -19,7 +20,6 @@
 #include "screenedge.h"
 #include "workspace.h"
 // KDE
-#include "opengl/glutils.h"
 #include <KConfigGroup>
 #include <KGlobalAccel>
 #include <KPluginMetaData>
diff --git a/src/scripting/tilemodel.cpp b/src/scripting/tilemodel.cpp
index 8b246fb6e5..ae78b2ad41 100644
--- a/src/scripting/tilemodel.cpp
+++ b/src/scripting/tilemodel.cpp
@@ -8,9 +8,7 @@
 */
 
 #include "tilemodel.h"
-#include "core/output.h"
 #include "tiles/tilemanager.h"
-#include "virtualdesktops.h"
 #include "workspace.h"
 
 #include <KConfigGroup>
diff --git a/src/scripting/tilemodel.h b/src/scripting/tilemodel.h
index 81fe1c13f8..55aaa56cd7 100644
--- a/src/scripting/tilemodel.h
+++ b/src/scripting/tilemodel.h
@@ -10,9 +10,7 @@
 #pragma once
 
 #include "tiles/customtile.h"
-#include "tiles/quicktile.h"
 #include "tiles/tile.h"
-#include "utils/common.h"
 #include <kwin_export.h>
 
 #include <QAbstractItemModel>
diff --git a/src/scripting/windowthumbnailitem.cpp b/src/scripting/windowthumbnailitem.cpp
index 01e4e926d0..ec9fdb9a77 100644
--- a/src/scripting/windowthumbnailitem.cpp
+++ b/src/scripting/windowthumbnailitem.cpp
@@ -12,16 +12,15 @@
 #include "core/rendertarget.h"
 #include "core/renderviewport.h"
 #include "effect/effect.h"
+#include "opengl/glframebuffer.h"
 #include "scene/itemrenderer.h"
 #include "scene/windowitem.h"
 #include "scene/workspacescene.h"
 #include "scripting_logging.h"
-#include "virtualdesktops.h"
 #include "window.h"
 #include "workspace.h"
 
 #include "opengl/gltexture.h"
-#include "opengl/glutils.h"
 
 #include <QQuickWindow>
 #include <QRunnable>
@@ -350,6 +349,7 @@ void WindowThumbnailItem::setWId(const QUuid &wId)
         updateImplicitSize();
         Q_EMIT clientChanged();
     }
+
     Q_EMIT wIdChanged();
 }