diff --git a/superset/models/helpers.py b/superset/models/helpers.py
index 327cc21efb6..7c39c1c0e00 100644
--- a/superset/models/helpers.py
+++ b/superset/models/helpers.py
@@ -244,7 +244,7 @@ def export_to_dict(
                         )
                         for child in getattr(self, c)
                     ],
-                    key=lambda k: sorted(k.items()),
+                    key=lambda k: sorted(str(k.items())),
                 )
 
         return dict_rep