diff --git a/src/plugins/qt4projectmanager/debugginghelperbuildtask.cpp b/src/plugins/qt4projectmanager/debugginghelperbuildtask.cpp
index ebf417a891e..1797c9c5285 100644
--- a/src/plugins/qt4projectmanager/debugginghelperbuildtask.cpp
+++ b/src/plugins/qt4projectmanager/debugginghelperbuildtask.cpp
@@ -106,6 +106,11 @@ DebuggingHelperBuildTask::DebuggingHelperBuildTask(const BaseQtVersion *version,
     m_qmakeCommand = version->qmakeCommand();
     m_makeCommand = tc->makeCommand();
     m_mkspec = version->mkspec();
+
+    // Make sure QtVersion cache is invalidated
+    connect(this, SIGNAL(finished(int,QString,DebuggingHelperBuildTask::Tools)),
+            QtVersionManager::instance(), SLOT(updateQtVersion(int)),
+            Qt::QueuedConnection);
 }
 
 DebuggingHelperBuildTask::~DebuggingHelperBuildTask()
diff --git a/src/plugins/qt4projectmanager/qmakestep.cpp b/src/plugins/qt4projectmanager/qmakestep.cpp
index dc8684cdcdd..45669a776fb 100644
--- a/src/plugins/qt4projectmanager/qmakestep.cpp
+++ b/src/plugins/qt4projectmanager/qmakestep.cpp
@@ -451,6 +451,8 @@ QMakeStepConfigWidget::QMakeStepConfigWidget(QMakeStep *step)
             this, SLOT(qtVersionChanged()));
     connect(step->qt4BuildConfiguration(), SIGNAL(qmakeBuildConfigurationChanged()),
             this, SLOT(qmakeBuildConfigChanged()));
+    connect(QtVersionManager::instance(), SIGNAL(qtVersionsUpdated(QString)),
+            this, SLOT(qtVersionsUpdated(QString)));
 }
 
 void QMakeStepConfigWidget::init()
@@ -482,6 +484,12 @@ void QMakeStepConfigWidget::qtVersionChanged()
     updateQmlDebuggingOption();
 }
 
+void QMakeStepConfigWidget::qtVersionsUpdated(const QString &qmakeCommand)
+{
+    if (m_step->qt4BuildConfiguration()->qtVersion()->qmakeCommand() == qmakeCommand)
+        qtVersionChanged();
+}
+
 void QMakeStepConfigWidget::qmakeBuildConfigChanged()
 {
     Qt4BuildConfiguration *bc = m_step->qt4BuildConfiguration();
@@ -510,7 +518,6 @@ void QMakeStepConfigWidget::linkQmlDebuggingLibraryChanged()
 {
     if (m_ignoreChange)
         return;
-    m_ui.qmlDebuggingLibraryCheckBox->setEnabled(m_step->isQmlDebuggingLibrarySupported());
     m_ui.qmlDebuggingLibraryCheckBox->setChecked(m_step->linkQmlDebuggingLibrary());
 
     updateSummaryLabel();
@@ -576,10 +583,6 @@ void QMakeStepConfigWidget::buildQmlDebuggingHelper()
     DebuggingHelperBuildTask *buildTask = new DebuggingHelperBuildTask(version,
                                                                        DebuggingHelperBuildTask::QmlDebugging);
 
-    connect(buildTask, SIGNAL(finished(int,QString,DebuggingHelperBuildTask::Tools)),
-            this, SLOT(debuggingHelperBuildFinished(int,QString)),
-            Qt::QueuedConnection);
-
     // pop up Application Output on error
     buildTask->showOutputOnError(true);
 
@@ -589,20 +592,6 @@ void QMakeStepConfigWidget::buildQmlDebuggingHelper()
                                                         QLatin1String("Qt4ProjectManager::BuildHelpers"));
 }
 
-void QMakeStepConfigWidget::debuggingHelperBuildFinished(int qtVersionId, const QString &output)
-{
-    BaseQtVersion *version = QtVersionManager::instance()->version(qtVersionId);
-    if (!version) // qt version got deleted in between
-        return;
-
-    if (version == m_step->qt4BuildConfiguration()->qtVersion()) {
-        m_ui.qmlDebuggingLibraryCheckBox->setChecked(m_step->linkQmlDebuggingLibrary());
-        updateSummaryLabel();
-        updateEffectiveQMakeCall();
-        updateQmlDebuggingOption();
-    }
-}
-
 void QMakeStepConfigWidget::updateSummaryLabel()
 {
     Qt4BuildConfiguration *qt4bc = m_step->qt4BuildConfiguration();
diff --git a/src/plugins/qt4projectmanager/qmakestep.h b/src/plugins/qt4projectmanager/qmakestep.h
index 69ac9cf30c1..0bfa41a7401 100644
--- a/src/plugins/qt4projectmanager/qmakestep.h
+++ b/src/plugins/qt4projectmanager/qmakestep.h
@@ -137,6 +137,7 @@ public:
 private slots:
     // slots for handling buildconfiguration/step signals
     void qtVersionChanged();
+    void qtVersionsUpdated(const QString &qmakeCommand);
     void qmakeBuildConfigChanged();
     void userArgumentsChanged();
     void linkQmlDebuggingLibraryChanged();
@@ -148,7 +149,6 @@ private slots:
 
     // other
     void buildQmlDebuggingHelper();
-    void debuggingHelperBuildFinished(int qtVersionId, const QString &output);
 
 private:
     void updateSummaryLabel();
diff --git a/src/plugins/qt4projectmanager/qtoptionspage.cpp b/src/plugins/qt4projectmanager/qtoptionspage.cpp
index dcc0f7d9934..78322581e4a 100644
--- a/src/plugins/qt4projectmanager/qtoptionspage.cpp
+++ b/src/plugins/qt4projectmanager/qtoptionspage.cpp
@@ -192,6 +192,9 @@ QtOptionsPageWidget::QtOptionsPageWidget(QWidget *parent, QList<BaseQtVersion *>
     connect(m_ui->cleanUpButton, SIGNAL(clicked()), this, SLOT(cleanUpQtVersions()));
     userChangedCurrentVersion();
     updateCleanUpButton();
+
+    connect(QtVersionManager::instance(), SIGNAL(qtVersionsUpdated(QString)),
+            this, SLOT(qtVersionsUpdated(QString)));
 }
 
 bool QtOptionsPageWidget::eventFilter(QObject *o, QEvent *e)
@@ -270,6 +273,7 @@ void QtOptionsPageWidget::debuggingHelperBuildFinished(int qtVersionId, const QS
     if (index == currentIndex()) {
         updateDebuggingHelperUi();
     }
+
     if (!success)
         showDebuggingBuildLog(item);
 }
@@ -304,6 +308,19 @@ void QtOptionsPageWidget::cleanUpQtVersions()
     updateCleanUpButton();
 }
 
+void QtOptionsPageWidget::qtVersionsUpdated(const QString &qmakeCommand)
+{
+    foreach (BaseQtVersion *version, m_versions) {
+        if (version->qmakeCommand() == qmakeCommand)
+            version->recheckDumper();
+    }
+    if (currentVersion()->qmakeCommand() == qmakeCommand) {
+        updateWidgets();
+        updateDescriptionLabel();
+        updateDebuggingHelperUi();
+    }
+}
+
 void QtOptionsPageWidget::buildDebuggingHelper(DebuggingHelperBuildTask::Tools tools)
 {
     const int index = currentIndex();
diff --git a/src/plugins/qt4projectmanager/qtoptionspage.h b/src/plugins/qt4projectmanager/qtoptionspage.h
index 08fd4d79b1c..3512fd14f15 100644
--- a/src/plugins/qt4projectmanager/qtoptionspage.h
+++ b/src/plugins/qt4projectmanager/qtoptionspage.h
@@ -107,6 +107,8 @@ private slots:
     void slotShowDebuggingBuildLog();
     void debuggingHelperBuildFinished(int qtVersionId, const QString &output, DebuggingHelperBuildTask::Tools tools);
     void cleanUpQtVersions();
+
+    void qtVersionsUpdated(const QString &qmakeCommand);
 };
 
 class QtOptionsPage : public Core::IOptionsPage
diff --git a/src/plugins/qt4projectmanager/qtversionmanager.cpp b/src/plugins/qt4projectmanager/qtversionmanager.cpp
index 37069c06632..f25eedc9def 100644
--- a/src/plugins/qt4projectmanager/qtversionmanager.cpp
+++ b/src/plugins/qt4projectmanager/qtversionmanager.cpp
@@ -381,6 +381,7 @@ void QtVersionManager::updateQtVersion(int id)
         if (v->qmakeCommand() == qmakeCommand)
             v->recheckDumper();
     }
+    emit qtVersionsUpdated(qmakeCommand);
 }
 
 void QtVersionManager::updateSettings()
diff --git a/src/plugins/qt4projectmanager/qtversionmanager.h b/src/plugins/qt4projectmanager/qtversionmanager.h
index ed7cd8ded1a..5903e96e988 100644
--- a/src/plugins/qt4projectmanager/qtversionmanager.h
+++ b/src/plugins/qt4projectmanager/qtversionmanager.h
@@ -118,6 +118,8 @@ public:
     QString popPendingMwcUpdate();
     QString popPendingGcceUpdate();
 signals:
+    // qt version information cache has been invalidated
+    void qtVersionsUpdated(const QString &qmakeCommand);
     void qtVersionsChanged(const QList<int> &uniqueIds);
     void updateExamples(QString, QString, QString);