diff --git a/payphone/cogs/calls/cog.py b/payphone/cogs/calls/cog.py
index 26b0a27..ecdb1e3 100644
--- a/payphone/cogs/calls/cog.py
+++ b/payphone/cogs/calls/cog.py
@@ -123,6 +123,8 @@ class Calls(base.Cog):
                     except errors.DiscordException:
                         pass
 
+        hung_up_channel_ids = [id for id in hung_up_channel_ids if id is not None]
+
         if len(hung_up_channel_ids) > 0:
             await models.Channel.filter(id__in=hung_up_channel_ids).update(call=None)
             await redis.srem(constants.CHANNELS_ONCALL_SET, *hung_up_channel_ids)