diff --git a/src/gui/widgets/Knob.cpp b/src/gui/widgets/Knob.cpp
index 7c6b26c36..f13dcc1dd 100644
--- a/src/gui/widgets/Knob.cpp
+++ b/src/gui/widgets/Knob.cpp
@@ -497,6 +497,7 @@ void Knob::contextMenuEvent( QContextMenuEvent * )
 void Knob::toggleScale()
 {
 	model()->setScaleLogarithmic( ! model()->isScaleLogarithmic() );
+	update();
 }