diff --git a/xul/content/commands.js b/xul/content/commands.js
--- a/xul/content/commands.js
+++ b/xul/content/commands.js
@@ -2478,24 +2478,27 @@ function cmdLeave(e)
             if (channelToLeave.joined)
                 channelToLeave.joined = false;
 
             if (e.deleteWhenDone)
                 channelToLeave.dispatch("delete-view");
         }
 
         return shouldContinue;
-    }
+    };
 
     if (!e.server)
     {
         display(getMsg(MSG_ERR_IMPROPER_VIEW, e.command.name), MT_ERROR);
         return;
     }
 
+    if (!e.hasOwnProperty("channelName") && e.channel)
+        e.channelName = e.channel.unicodeName;
+
     if (e.hasOwnProperty("channelName"))
     {
         if (!e.channelName)
         {
             // No channel specified and command not sent from a channel view
             display(getMsg(MSG_ERR_NEED_CHANNEL, e.command.name), MT_ERROR);
             return;
         }