diff --git a/src/src/Rendering/Measure/RulerAnnotationActor.cpp b/src/src/Rendering/Measure/RulerAnnotationActor.cpp
index f0e46e5..cbc8fa6 100644
--- a/src/src/Rendering/Measure/RulerAnnotationActor.cpp
+++ b/src/src/Rendering/Measure/RulerAnnotationActor.cpp
@@ -53,8 +53,6 @@ RulerAnnotationActor::RulerAnnotationActor()
     //textProperty->SetFrameColor(1.0,0.0,0.0);
     textProperty->SetBackgroundColor(1.0, 0.0, 0.0);
     textProperty->SetBackgroundOpacity(0.3);
-    this->AddObserver(DraggableStyleEvents::RightButtonClickEvent, this,
-                      &RulerAnnotationActor::selfCalibCb);
     mUnitmm = QCoreApplication::translate("RulerAnnotationActor","mm");
     mUnitcm = QCoreApplication::translate("RulerAnnotationActor","cm");
     mDistance = QCoreApplication::translate("RulerAnnotationActor","Distance");