diff --git a/vespa/PolygonMeshProcessing/vtkCGALMeshDeformation.cxx b/vespa/PolygonMeshProcessing/vtkCGALMeshDeformation.cxx
index 8af35e75be3c3fbd7de935e186de41084e4f7872..893ae9682aebaa1b0f1ab3f30f8f0ad79ee2eda1 100644
--- a/vespa/PolygonMeshProcessing/vtkCGALMeshDeformation.cxx
+++ b/vespa/PolygonMeshProcessing/vtkCGALMeshDeformation.cxx
@@ -92,6 +92,12 @@ int vtkCGALMeshDeformation::RequestData(
     extractSelection->SetInputData(1, roiSel);
     extractSelection->Update();
     roi->ShallowCopy(extractSelection->GetOutputDataObject(0));
+    if (!roi || roi->GetNumberOfPoints() == 0)
+    {
+      vtkErrorMacro("Not a valid selection, need points.");
+      output->ShallowCopy(input);
+      return 0;
+    }
   }
   else
   {
diff --git a/vespa/PolygonMeshProcessing/vtkCGALRegionFairing.cxx b/vespa/PolygonMeshProcessing/vtkCGALRegionFairing.cxx
index 4254cb1a682c83de3bf548fc792ddd4300d909c6..7ecc3f10be1478c46e0a585e143b7bce7c46610d 100644
--- a/vespa/PolygonMeshProcessing/vtkCGALRegionFairing.cxx
+++ b/vespa/PolygonMeshProcessing/vtkCGALRegionFairing.cxx
@@ -72,6 +72,12 @@ int vtkCGALRegionFairing::RequestData(
   extractSelection->SetInputData(1, inputSel);
   extractSelection->Update();
   vtkPointSet* dataSel = vtkPointSet::SafeDownCast(extractSelection->GetOutputDataObject(0));
+  if (!dataSel || dataSel->GetNumberOfPoints() == 0)
+  {
+    vtkErrorMacro("Not a valid selection, need points.");
+    output->ShallowCopy(input);
+    return 0;
+  }
 
   // Create the triangle mesh for CGAL
   // --------------------------------