diff --git a/dota.py b/dota.py
index 9795472..85a2e9f 100644
--- a/dota.py
+++ b/dota.py
@@ -213,7 +213,9 @@ def serialize_match_for_discord(match_):
       is_radiant = player['is_radiant']
       break
   win = is_radiant == match_['radiant_win']
-  if match_['party_size'] > 1:
+  if not match_['party_size']:
+    summary = f"??黑 {match_['duration']}"
+  elif match_['party_size'] > 1:
     summary = f"{match_['party_size']}黑 {match_['duration']}"
   else:
     summary = f"单排 {match_['duration']}"