diff --git a/src/Mod/TechDraw/App/DimensionReferences.cpp b/src/Mod/TechDraw/App/DimensionReferences.cpp
index bff174dc2a..6ff8cb462e 100644
--- a/src/Mod/TechDraw/App/DimensionReferences.cpp
+++ b/src/Mod/TechDraw/App/DimensionReferences.cpp
@@ -113,7 +113,9 @@ Part::TopoShape ReferenceEntry::asTopoShape() const
 {
 //    Base::Console().Message("RE::asTopoShape()\n");
     TopoDS_Shape geom = getGeometry();
-
+    if (geom.IsNull()) {
+        throw Base::RuntimeError("Dimension Reference has null geometry");
+    }
     if (geom.ShapeType() == TopAbs_VERTEX) {
         TopoDS_Vertex vert = TopoDS::Vertex(geom);
         return asTopoShapeVertex(vert);