diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index 5b9704228b5..b2ea35305ac 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1721,6 +1721,10 @@ QAction * QDockWidget::toggleViewAction() const
     invisible). This happens when the widget is hidden or shown, as
     well as when it is docked in a tabbed dock area and its tab
     becomes selected or unselected.
+
+    \note The signal can differ from QWidget::isVisible(). This can be the case, if
+    a dock widget is minimized or tabified and associated to a non-selected or
+    inactive tab.
 */
 
 /*!
diff --git a/src/widgets/widgets/qdockwidget.h b/src/widgets/widgets/qdockwidget.h
index f524a884232..8123bbb7298 100644
--- a/src/widgets/widgets/qdockwidget.h
+++ b/src/widgets/widgets/qdockwidget.h
@@ -72,7 +72,7 @@ Q_SIGNALS:
     void featuresChanged(QDockWidget::DockWidgetFeatures features);
     void topLevelChanged(bool topLevel);
     void allowedAreasChanged(Qt::DockWidgetAreas allowedAreas);
-    void visibilityChanged(bool visible);
+    void visibilityChanged(bool visible); //TODO depricate in Qt7: Better listen to hide/show events
     void dockLocationChanged(Qt::DockWidgetArea area);
 
 protected: