diff --git a/RoomsEyeView/Resources/UI/qSlicerRoomsEyeViewModule.ui b/RoomsEyeView/Resources/UI/qSlicerRoomsEyeViewModule.ui
index 4e42607f..22915dc7 100644
--- a/RoomsEyeView/Resources/UI/qSlicerRoomsEyeViewModule.ui
+++ b/RoomsEyeView/Resources/UI/qSlicerRoomsEyeViewModule.ui
@@ -449,6 +449,9 @@
          <string>vtkMRMLRTBeamNode</string>
         </stringlist>
        </property>
+       <property name="noneEnabled">
+        <bool>true</bool>
+       </property>
       </widget>
      </item>
      <item row="2" column="1">
diff --git a/RoomsEyeView/qSlicerRoomsEyeViewModuleWidget.cxx b/RoomsEyeView/qSlicerRoomsEyeViewModuleWidget.cxx
index 281d1ad2..688203e8 100644
--- a/RoomsEyeView/qSlicerRoomsEyeViewModuleWidget.cxx
+++ b/RoomsEyeView/qSlicerRoomsEyeViewModuleWidget.cxx
@@ -400,9 +400,6 @@ void qSlicerRoomsEyeViewModuleWidget::onBeamNodeChanged(vtkMRMLNode* node)
   paramNode->SetAndObserveBeamNode(beamNode);
   paramNode->DisableModifiedEventOff();
 
-  // Trigger update of transforms based on selected beam
-  beamNode->InvokeCustomModifiedEvent(vtkMRMLRTBeamNode::BeamTransformModified);
-
   // Show only selected beam, hide others
   std::vector<vtkMRMLNode*> beamNodes;
   this->mrmlScene()->GetNodesByClass("vtkMRMLRTBeamNode", beamNodes);
@@ -413,6 +410,14 @@ void qSlicerRoomsEyeViewModuleWidget::onBeamNodeChanged(vtkMRMLNode* node)
       shNode->GetItemByDataNode(currentBeamNode), (currentBeamNode == beamNode ? 1 : 0) );
   }
 
+  if (!beamNode)
+  {
+    return;
+  }
+
+  // Trigger update of transforms based on selected beam
+  beamNode->InvokeCustomModifiedEvent(vtkMRMLRTBeamNode::BeamTransformModified);
+
   // Select patient segmentation
   vtkMRMLRTPlanNode* planNode = beamNode->GetParentPlanNode();
   if (!planNode)