diff --git a/scripting/workspace_wrapper.cpp b/scripting/workspace_wrapper.cpp
index fb7371190..b452249fb 100644
--- a/scripting/workspace_wrapper.cpp
+++ b/scripting/workspace_wrapper.cpp
@@ -30,6 +30,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 
 #include <QDesktopWidget>
+#include <QApplication>
 
 namespace KWin {
 
diff --git a/sm.cpp b/sm.cpp
index 1b399429d..632b36528 100644
--- a/sm.cpp
+++ b/sm.cpp
@@ -33,6 +33,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QSocketNotifier>
 #include <QSessionManager>
 #include <kdebug.h>
+#include <KDE/KApplication>
 
 namespace KWin
 {
diff --git a/sm.h b/sm.h
index a0f6e3c7b..2aee595dc 100644
--- a/sm.h
+++ b/sm.h
@@ -23,7 +23,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define KWIN_SM_H
 
 #include <QDataStream>
-#include <kapplication.h>
 #include <ksessionmanager.h>
 #include <netwm_def.h>
 #include <QRect>
diff --git a/tabbox/declarative.cpp b/tabbox/declarative.cpp
index 4d87c8f8c..a7482bfae 100644
--- a/tabbox/declarative.cpp
+++ b/tabbox/declarative.cpp
@@ -22,6 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "tabboxhandler.h"
 #include "clientmodel.h"
 // Qt
+#include <QApplication>
 #include <QtDeclarative/qdeclarative.h>
 #include <QtDeclarative/QDeclarativeContext>
 #include <QtDeclarative/QDeclarativeEngine>
diff --git a/workspace.cpp b/workspace.cpp
index b7b68d8c1..c0126411c 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -61,6 +61,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "xcbutils.h"
 // KDE
 #include <kdeversion.h>
+#include <KDE/KApplication>
 #include <KDE/KActionCollection>
 #include <KDE/KCmdLineArgs>
 #include <KDE/KConfig>
diff --git a/workspace.h b/workspace.h
index fb87e00db..6b6707050 100644
--- a/workspace.h
+++ b/workspace.h
@@ -39,6 +39,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 class QStringList;
 class KConfig;
+class KConfigGroup;
 class KActionCollection;
 class KShortcut;
 class KStartupInfo;