diff --git a/src/src/Interaction/ActorDraggableInteractorStyle.cpp b/src/src/Interaction/ActorDraggableInteractorStyle.cpp
index 4950f9b..45d1446 100644
--- a/src/src/Interaction/ActorDraggableInteractorStyle.cpp
+++ b/src/src/Interaction/ActorDraggableInteractorStyle.cpp
@@ -354,6 +354,7 @@ void ActorDraggableInteractorStyle::UnActiveMeasure() {
     if (this->measure) {
         this->measure->onTerminate(this->Interactor);
         this->measure->ForceDelete();
+        this->measure = nullptr;
     }
     this->EndMeasure();
     this->measure = nullptr;
diff --git a/src/src/Rendering/Viewer/DICOMImageViewer.cxx b/src/src/Rendering/Viewer/DICOMImageViewer.cxx
index 5b4e61e..74f16fc 100644
--- a/src/src/Rendering/Viewer/DICOMImageViewer.cxx
+++ b/src/src/Rendering/Viewer/DICOMImageViewer.cxx
@@ -1153,6 +1153,7 @@ void DICOMImageViewer::ClearCurrentSliceMeasure() const {
 }
 
 void DICOMImageViewer::AddMeasures(vtkObject *, unsigned long eventid, void *calldata) {
+    if (!calldata) return ;
     auto m = static_cast<Measure *>(calldata);
     if (m->Valid()) {
         measureStore->Store(SERIES_UID, this->SliceIJK, this->ImageMapper->GetSliceNumber(), m);