diff --git a/discord_bot.py b/discord_bot.py
index c94c296..355e366 100644
--- a/discord_bot.py
+++ b/discord_bot.py
@@ -42,6 +42,7 @@ async def send_message(channel):
 
 @bot.command(description="获取最近战绩", name='recent_matches') # this decorator makes a slash command
 async def get_friends_recent_matches(ctx, name, match_count=5): # a slash command will be created with the name "ping"
+  await ctx.defer()
   logger.info(f"get_friends_recent_matches {name} {match_count}")
   friends = dota.Friend.filter(name=name)
   match_count = int(match_count)
diff --git a/dota.py b/dota.py
index 5d48887..9795472 100644
--- a/dota.py
+++ b/dota.py
@@ -49,7 +49,7 @@ class Match(BaseModel):
   start_time = peewee.DateTimeField()
   duration = peewee.IntegerField()
   radiant_win = peewee.BooleanField()
-  party_size = peewee.IntegerField()
+  party_size = peewee.IntegerField(null=True)
 
   def serialize_match(self):
     try: