diff --git a/holoviews/core/util.py b/holoviews/core/util.py
index e08b5af4d9..54b46bda40 100644
--- a/holoviews/core/util.py
+++ b/holoviews/core/util.py
@@ -96,7 +96,7 @@ def default(self, obj):
         elif isinstance(obj, np.ndarray):
             return obj.tolist()
         if pd and isinstance(obj, (pd.Series, pd.DataFrame)):
-            return repr(sorted(list(obj.to_dict().items())))
+            return obj.to_csv().encode('utf-8')
         elif isinstance(obj, self.string_hashable):
             return str(obj)
         elif isinstance(obj, self.repr_hashable):