diff --git a/src/prefs/koprefsdialogcolorsandfonts.h b/src/prefs/koprefsdialogcolorsandfonts.h
index 8dda0ce3619be774d8ed32df9898640a540e76ff..87676c672b6389c9fc666a52fffc7d59c0c31c99 100644
--- a/src/prefs/koprefsdialogcolorsandfonts.h
+++ b/src/prefs/koprefsdialogcolorsandfonts.h
@@ -13,10 +13,8 @@
 #include "kprefsdialog.h"
 #include <QWidget>
 
-class QLabel;
 class QComboBox;
 class KColorButton;
-class QCheckBox;
 namespace Akonadi {
 class CollectionComboBox;
 }
diff --git a/src/prefs/koprefsdialoggroupscheduling.h b/src/prefs/koprefsdialoggroupscheduling.h
index 55d3e660ebc55aea8b799ed0904823033aef8032..c5051f381018e60ba0b0113f67d6f56f585b40b0 100644
--- a/src/prefs/koprefsdialoggroupscheduling.h
+++ b/src/prefs/koprefsdialoggroupscheduling.h
@@ -11,7 +11,6 @@
 #define KOPREFSDIALOGGROUPSCHEDULING_H
 
 #include "kprefsdialog.h"
-class QCheckBox;
 class KOPrefsDialogGroupScheduling : public Korganizer::KPrefsModule
 {
     Q_OBJECT
diff --git a/src/prefs/koprefsdialogmain.h b/src/prefs/koprefsdialogmain.h
index 1989ca08c4079e1e9e5721f2143aac785029ec7d..72a48b0b72289c2e917de131072abe17eeea0f01 100644
--- a/src/prefs/koprefsdialogmain.h
+++ b/src/prefs/koprefsdialogmain.h
@@ -11,8 +11,6 @@
 #define KOPREFSDIALOGMAIN_H
 
 #include "kprefsdialog.h"
-class QCheckBox;
-class QLineEdit;
 
 class KOPrefsDialogMain : public Korganizer::KPrefsModule
 {
diff --git a/src/prefs/koprefsdialogtime.h b/src/prefs/koprefsdialogtime.h
index 5a2e363896e73fa6204588eb772dbfc9e01253c2..18b86156b590a885b923dc545bcbf6cc6adf1cf2 100644
--- a/src/prefs/koprefsdialogtime.h
+++ b/src/prefs/koprefsdialogtime.h
@@ -14,10 +14,6 @@
 class QSpinBox;
 class KComboBox;
 class QCheckBox;
-class KUrlRequester;
-class KTimeComboBox;
-class QComboBox;
-class QTimeEdit;
 namespace KPIM {
 class KCheckComboBox;
 }
diff --git a/src/prefs/koprefsdialogviews.h b/src/prefs/koprefsdialogviews.h
index ddc34adf4cb5b517826835108ec14f57342c98dd..aff52595e8c04a50fc12fd1bea3128921dd851fc 100644
--- a/src/prefs/koprefsdialogviews.h
+++ b/src/prefs/koprefsdialogviews.h
@@ -13,8 +13,6 @@
 #include "kprefsdialog.h"
 
 class KItemIconCheckCombo;
-class QCheckBox;
-class QSpinBox;
 
 class KOPrefsDialogViews : public Korganizer::KPrefsModule
 {