diff --git a/effects/windowgeometry/windowgeometry.cpp b/effects/windowgeometry/windowgeometry.cpp
index ec2f79b515..1290790351 100644
--- a/effects/windowgeometry/windowgeometry.cpp
+++ b/effects/windowgeometry/windowgeometry.cpp
@@ -27,7 +27,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QStringBuilder>
 #include <kwinconfig.h>
 #include <kconfiggroup.h>
-#include <kwindowsystem.h>
 #include <KGlobalAccel>
 #include <KLocalizedString>
 
diff --git a/tabbox/tabboxhandler.cpp b/tabbox/tabboxhandler.cpp
index afb48fbb35..f9de5dec2a 100644
--- a/tabbox/tabboxhandler.cpp
+++ b/tabbox/tabboxhandler.cpp
@@ -47,7 +47,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KLocalizedString>
 #include <KProcess>
 #include <KServiceTypeTrader>
-#include <KWindowSystem>
 
 namespace KWin
 {
diff --git a/workspace.cpp b/workspace.cpp
index 7cbe81ebac..dc066dd129 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -67,7 +67,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KLocalizedString>
 #include <KStartupInfo>
 #include <KWindowInfo>
-#include <KWindowSystem>
 // Qt
 #include <QtConcurrentRun>