diff --git a/src/Gui/PreferencePages/DlgSettingsLightSources.cpp b/src/Gui/PreferencePages/DlgSettingsLightSources.cpp
index d39fe4bf50..034017a009 100644
--- a/src/Gui/PreferencePages/DlgSettingsLightSources.cpp
+++ b/src/Gui/PreferencePages/DlgSettingsLightSources.cpp
@@ -327,6 +327,10 @@ void DlgSettingsLightSources::resetSettingsToDefaults()
 {
     PreferencePage::resetSettingsToDefaults();
 
+    hGrp->RemoveASCII("HeadlightDirection");
+    hGrp->RemoveASCII("BacklightDirection");
+    hGrp->RemoveASCII("FillLightDirection");
+
     loadSettings();
     configureViewer();
 }