diff --git a/src/DockAreaTabBar.cpp b/src/DockAreaTabBar.cpp
index 898fc48..48e3c22 100644
--- a/src/DockAreaTabBar.cpp
+++ b/src/DockAreaTabBar.cpp
@@ -108,6 +108,9 @@ void DockAreaTabBarPrivate::updateTabs()
 		{
 			TabWidget->show();
 			TabWidget->setActiveTab(true);
+			// Sometimes the synchronous calculation of the rectangular area fails
+			// Therefore we use QTimer::singleShot here to execute the call
+			// within the event loop - see #520
 			QTimer::singleShot(0, [&, TabWidget]{
 			    _this->ensureWidgetVisible(TabWidget);
 			});