diff --git a/samples/qt/OCCTOverview/src/ApplicationCommon.h b/samples/qt/OCCTOverview/src/ApplicationCommon.h
index d37bf8be4d..a93dd3e4dc 100644
--- a/samples/qt/OCCTOverview/src/ApplicationCommon.h
+++ b/samples/qt/OCCTOverview/src/ApplicationCommon.h
@@ -71,7 +71,7 @@ enum ApplicationType
 
 
 //! Main application window
-class COMMONSAMPLE_EXPORT ApplicationCommonWindow: public QMainWindow
+class ApplicationCommonWindow: public QMainWindow
 {
   Q_OBJECT
 
diff --git a/samples/qt/OCCTOverview/src/DocumentCommon.h b/samples/qt/OCCTOverview/src/DocumentCommon.h
index b9c0fd312f..565802be4c 100644
--- a/samples/qt/OCCTOverview/src/DocumentCommon.h
+++ b/samples/qt/OCCTOverview/src/DocumentCommon.h
@@ -35,7 +35,7 @@
 class ApplicationCommonWindow;
 
 //! Implements visualization of samples content
-class COMMONSAMPLE_EXPORT DocumentCommon : public QObject
+class DocumentCommon : public QObject
 {
   Q_OBJECT
 public:
diff --git a/samples/qt/OCCTOverview/src/View.cxx b/samples/qt/OCCTOverview/src/View.cxx
index 4604805cb0..929e5e8ec5 100644
--- a/samples/qt/OCCTOverview/src/View.cxx
+++ b/samples/qt/OCCTOverview/src/View.cxx
@@ -438,7 +438,9 @@ void View::initViewActions()
     aHlrActionGroup->addAction(aHlrOnAction);
     myViewActions[ViewAction_HlrOn] = aHlrOnAction;
 
-    myViewActions[ViewAction_Transparency] = RegisterAction(":/icons/tool_transparency.png", tr("Transparency"));
+    QAction* aTransparencyAction = RegisterAction(":/icons/tool_transparency.png", tr("Transparency"));
+    connect(aTransparencyAction, SIGNAL(triggered()), this, SLOT(onTransparency()));
+    myViewActions[ViewAction_Transparency] = aTransparencyAction;
   }
 }