diff --git a/Framework/Geometry/inc/MantidGeometry/Rendering/GeometryTriangulator.h b/Framework/Geometry/inc/MantidGeometry/Rendering/GeometryTriangulator.h
index 865dbd8a7003b4e6153f5d9cba8aa311e84e27c8..e7a6b86a5fc1a74d84d53e9701f90986e96e4c42 100644
--- a/Framework/Geometry/inc/MantidGeometry/Rendering/GeometryTriangulator.h
+++ b/Framework/Geometry/inc/MantidGeometry/Rendering/GeometryTriangulator.h
@@ -52,6 +52,7 @@ public:
   GeometryTriangulator(const CSGObject *obj = nullptr);
   GeometryTriangulator(const MeshObject *obj);
   GeometryTriangulator(const GeometryTriangulator &) = delete;
+  GeometryTriangulator &operator=(const GeometryTriangulator &) = delete;
   ~GeometryTriangulator();
   void triangulate();
   void generateMesh();