diff --git a/postprocessor.py b/postprocessor.py
index 92d8e33..ed0c6d0 100644
--- a/postprocessor.py
+++ b/postprocessor.py
@@ -481,7 +481,7 @@ class PostProcessor(HDF5Container):
             pos = dset.points
         except AttributeError:
             pos = dset["pos"]
-        pos = pos - np.array(self.save.root.maps._v_attrs.center)
+        pos = pos - np.array(self.pp_params.disk.center)
         return pos
 
     def getter_vect_r(self, dset, name_vect):