diff --git a/python/tests/test_VTK.py b/python/tests/test_VTK.py
index 26d1c4a53..68224ff33 100644
--- a/python/tests/test_VTK.py
+++ b/python/tests/test_VTK.py
@@ -20,7 +20,7 @@ def default():
     """Simple VTK."""
     cells = np.array([5,6,7],int)
     size  = np.array([.6,1.,.5])
-    return VTK.from_rectilinear_grid(cells,size)
+    return VTK.from_image_data(cells,size)
 
 class TestVTK:
 
@@ -116,7 +116,7 @@ class TestVTK:
 
     def test_add_extension(self,tmp_path,default):
         default.save(tmp_path/'default.txt',parallel=False)
-        assert os.path.isfile(tmp_path/'default.txt.vtr')
+        assert os.path.isfile(tmp_path/'default.txt.vti')
 
 
     def test_invalid_get(self,default):
@@ -160,7 +160,7 @@ class TestVTK:
     def test_comments(self,tmp_path,default):
         default.add_comments(['this is a comment'])
         default.save(tmp_path/'with_comments',parallel=False)
-        new = VTK.load(tmp_path/'with_comments.vtr')
+        new = VTK.load(tmp_path/'with_comments.vti')
         assert new.get_comments() == ['this is a comment']
 
     @pytest.mark.xfail(int(vtk.vtkVersion.GetVTKVersion().split('.')[0])<8, reason='missing METADATA')