diff --git a/src/Gui/GuiApplicationNativeEventAware.cpp b/src/Gui/GuiApplicationNativeEventAware.cpp
index 1e97f0abd..2ae0d3dd0 100644
--- a/src/Gui/GuiApplicationNativeEventAware.cpp
+++ b/src/Gui/GuiApplicationNativeEventAware.cpp
@@ -100,6 +100,9 @@ void Gui::GUIApplicationNativeEventAware::initSpaceball(QMainWindow *window)
 
 bool Gui::GUIApplicationNativeEventAware::processSpaceballEvent(QObject *object, QEvent *event)
 {
+    if (!activeWindow())
+        return true;
+
     QApplication::notify(object, event);
     if (event->type() == Spaceball::MotionEvent::MotionEventType)
     {