diff --git a/motmetrics/mot.py b/motmetrics/mot.py
index a6bf0e76..aea36c87 100644
--- a/motmetrics/mot.py
+++ b/motmetrics/mot.py
@@ -340,6 +340,7 @@ def new_event_dataframe():
             ]),
             index=idx
         )
+        df.sort_index(level=_INDEX_FIELDS)
         return df
 
     @staticmethod
@@ -373,6 +374,7 @@ def new_event_dataframe_with_data(indices, events):
             names=_INDEX_FIELDS)
         df = pd.concat(series, axis=1)
         df.index = idx
+        df.sort_index(level=_INDEX_FIELDS)
         return df
 
     @staticmethod