diff --git a/src/plugins/qt4projectmanager/qt-s60/symbianqtversion.cpp b/src/plugins/qt4projectmanager/qt-s60/symbianqtversion.cpp
index 02d568e5724..e1c1e25a513 100644
--- a/src/plugins/qt4projectmanager/qt-s60/symbianqtversion.cpp
+++ b/src/plugins/qt4projectmanager/qt-s60/symbianqtversion.cpp
@@ -41,6 +41,7 @@
 #include <projectexplorer/toolchainmanager.h>
 #include <qtsupport/qtsupportconstants.h>
 #include <utils/pathchooser.h>
+#include <utils/environment.h>
 #include <proparser/profileevaluator.h>
 
 #include <QtCore/QCoreApplication>
diff --git a/src/plugins/qtsupport/baseqtversion.cpp b/src/plugins/qtsupport/baseqtversion.cpp
index 03eb34594a6..0f5d84801c1 100644
--- a/src/plugins/qtsupport/baseqtversion.cpp
+++ b/src/plugins/qtsupport/baseqtversion.cpp
@@ -45,6 +45,7 @@
 #include <projectexplorer/toolchainmanager.h>
 #include <projectexplorer/persistentsettings.h>
 
+#include <utils/environment.h>
 #include <utils/synchronousprocess.h>
 
 #include <QtCore/QDir>
diff --git a/src/plugins/qtsupport/baseqtversion.h b/src/plugins/qtsupport/baseqtversion.h
index 65ea6976d61..7f6ee164feb 100644
--- a/src/plugins/qtsupport/baseqtversion.h
+++ b/src/plugins/qtsupport/baseqtversion.h
@@ -38,10 +38,17 @@
 #include <projectexplorer/abi.h>
 #include <projectexplorer/headerpath.h>
 #include <projectexplorer/task.h>
-#include <projectexplorer/ioutputparser.h>
-#include <utils/environment.h>
 
 #include <QtCore/QVariantMap>
+#include <QtGui/QWidget>
+
+namespace Utils {
+class Environment;
+} // namespace Utils
+
+namespace ProjectExplorer {
+class IOutputParser;
+} // namespace ProjectExplorer
 
 QT_BEGIN_NAMESPACE
 class ProFileEvaluator;
diff --git a/src/plugins/qtsupport/debugginghelperbuildtask.cpp b/src/plugins/qtsupport/debugginghelperbuildtask.cpp
index e59e31937db..9330442ad97 100644
--- a/src/plugins/qtsupport/debugginghelperbuildtask.cpp
+++ b/src/plugins/qtsupport/debugginghelperbuildtask.cpp
@@ -39,6 +39,7 @@
 #include <coreplugin/messagemanager.h>
 #include <projectexplorer/abi.h>
 #include <projectexplorer/toolchainmanager.h>
+#include <projectexplorer/toolchain.h>
 #include <projectexplorer/debugginghelper.h>
 #include <projectexplorer/abi.h>
 #include <utils/qtcassert.h>
diff --git a/src/plugins/qtsupport/debugginghelperbuildtask.h b/src/plugins/qtsupport/debugginghelperbuildtask.h
index aa836e128d2..8d6e599a9ee 100644
--- a/src/plugins/qtsupport/debugginghelperbuildtask.h
+++ b/src/plugins/qtsupport/debugginghelperbuildtask.h
@@ -41,6 +41,10 @@
 #include <QtCore/QFutureInterface>
 #include <QtCore/QMetaType>
 
+namespace ProjectExplorer {
+class ToolChain;
+} // namespace ProjectExplorer
+
 namespace QtSupport {
 class BaseQtVersion;
 
diff --git a/src/plugins/qtsupport/gettingstartedwelcomepage.cpp b/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
index 794d46525cd..fe3f3d5e383 100644
--- a/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
+++ b/src/plugins/qtsupport/gettingstartedwelcomepage.cpp
@@ -38,6 +38,7 @@
 #include <utils/fileutils.h>
 
 #include <coreplugin/coreplugin.h>
+#include <coreplugin/icore.h>
 #include <coreplugin/helpmanager.h>
 #include <projectexplorer/projectexplorer.h>
 
@@ -107,6 +108,11 @@ GettingStartedWelcomePage::GettingStartedWelcomePage()
 {
 }
 
+QUrl GettingStartedWelcomePage::pageLocation() const
+{
+    return QUrl::fromLocalFile(Core::ICore::instance()->resourcePath() + QLatin1String("/welcomescreen/gettingstarted.qml"));
+}
+
 void GettingStartedWelcomePage::facilitateQml(QDeclarativeEngine *engine)
 {
     m_engine = engine;
diff --git a/src/plugins/qtsupport/gettingstartedwelcomepage.h b/src/plugins/qtsupport/gettingstartedwelcomepage.h
index ebe2318f9f3..fa2ace2a040 100644
--- a/src/plugins/qtsupport/gettingstartedwelcomepage.h
+++ b/src/plugins/qtsupport/gettingstartedwelcomepage.h
@@ -34,10 +34,8 @@
 #define GETTINGSTARTEDWELCOMEPLUGIN_H
 
 #include <utils/iwelcomepage.h>
-#include <coreplugin/icore.h>
 
-#include <QtGui/QStringListModel>
-#include <QtDeclarative/QDeclarativeItem>
+#include <QtCore/QStringList>
 
 QT_BEGIN_NAMESPACE
 class QDeclarativeEngine;
@@ -57,7 +55,7 @@ class GettingStartedWelcomePage : public Utils::IWelcomePage
 public:
     GettingStartedWelcomePage();
 
-    QUrl pageLocation() const { return QUrl::fromLocalFile(Core::ICore::instance()->resourcePath() + QLatin1String("/welcomescreen/gettingstarted.qml")); }
+    QUrl pageLocation() const;
     QString title() const { return tr("Getting Started");}
     int priority() const { return 10; }
     void facilitateQml(QDeclarativeEngine *);
diff --git a/src/plugins/qtsupport/qtparser.cpp b/src/plugins/qtsupport/qtparser.cpp
index 1146d8a9e75..9d11f5298f3 100644
--- a/src/plugins/qtsupport/qtparser.cpp
+++ b/src/plugins/qtsupport/qtparser.cpp
@@ -39,10 +39,8 @@
 using namespace QtSupport;
 using ProjectExplorer::Task;
 
-namespace {
-    // opt. drive letter + filename: (2 brackets)
-    const char * const FILE_PATTERN = "^(([A-Za-z]:)?[^:]+\\.[^:]+)";
-}
+// opt. drive letter + filename: (2 brackets)
+static const char FILE_PATTERN[] = "^(([A-Za-z]:)?[^:]+\\.[^:]+)";
 
 QtParser::QtParser()
 {
diff --git a/src/plugins/qtsupport/qtversionfactory.cpp b/src/plugins/qtsupport/qtversionfactory.cpp
index 8488993c786..b72a07d5f66 100644
--- a/src/plugins/qtsupport/qtversionfactory.cpp
+++ b/src/plugins/qtsupport/qtversionfactory.cpp
@@ -33,6 +33,7 @@
 #include "qtversionfactory.h"
 #include "profilereader.h"
 #include "qtversionmanager.h"
+#include "baseqtversion.h"
 
 #include <extensionsystem/pluginmanager.h>
 #include <QtCore/QSettings>
diff --git a/src/plugins/qtsupport/qtversionfactory.h b/src/plugins/qtsupport/qtversionfactory.h
index 41d150e3424..373c830d96a 100644
--- a/src/plugins/qtsupport/qtversionfactory.h
+++ b/src/plugins/qtsupport/qtversionfactory.h
@@ -33,14 +33,18 @@
 #ifndef QTVERSIONFACTORY_H
 #define QTVERSIONFACTORY_H
 
-#include "baseqtversion.h"
 #include "qtsupport_global.h"
 
 #include <QtCore/QObject>
 #include <QtCore/QVariantMap>
 
+QT_FORWARD_DECLARE_CLASS(QSettings)
+QT_FORWARD_DECLARE_CLASS(ProFileEvaluator)
+
 namespace QtSupport {
 
+class BaseQtVersion;
+
 class QTSUPPORT_EXPORT QtVersionFactory : public QObject
 {
     Q_OBJECT
diff --git a/src/plugins/qtsupport/qtversionmanager.h b/src/plugins/qtsupport/qtversionmanager.h
index 9ab0f65529a..c9e3c480be6 100644
--- a/src/plugins/qtsupport/qtversionmanager.h
+++ b/src/plugins/qtsupport/qtversionmanager.h
@@ -36,14 +36,8 @@
 #include "qtsupport_global.h"
 #include "baseqtversion.h"
 
-#include <projectexplorer/abi.h>
-
-#include <QtCore/QHash>
 #include <QtCore/QSet>
-#include <QtCore/QSharedPointer>
-#include <QtCore/QFutureInterface>
 #include <QtCore/QStringList>
-#include <QtCore/QVariantMap>
 
 namespace Utils {
 class Environment;
@@ -56,8 +50,6 @@ class Task;
 }
 
 namespace QtSupport {
-class BaseQtVersion;
-
 namespace Internal {
 class QtOptionsPageWidget;
 class QtOptionsPage;
diff --git a/src/plugins/remotelinux/maemoqtversion.cpp b/src/plugins/remotelinux/maemoqtversion.cpp
index 56d5105daeb..167bc2cedec 100644
--- a/src/plugins/remotelinux/maemoqtversion.cpp
+++ b/src/plugins/remotelinux/maemoqtversion.cpp
@@ -40,6 +40,7 @@
 #include <QtCore/QCoreApplication>
 #include <QtCore/QFile>
 #include <QtCore/QDir>
+#include <QtCore/QTextStream>
 
 using namespace Qt4ProjectManager;