diff --git a/dota.py b/dota.py
index b55b4e0..5d48887 100644
--- a/dota.py
+++ b/dota.py
@@ -130,8 +130,10 @@ class Friend(BaseModel):
     }
     for match_ in matches[:limit]:
       duration = '%d:%02d:%02d' % utils.convert_seconds_to_hms(match_['duration'])
-      if match_['party_size'] > 1:
+      if match_['party_size'] and match_['party_size'] > 1:
         summary = f"{match_['party_size']}黑 {duration}"
+      elif match_['party_size'] == None:
+        summary = f"??黑 {duration}"
       else:
         summary = f"单排 {duration}"