diff --git a/app/controllers/concerns/bbb_server.rb b/app/controllers/concerns/bbb_server.rb
index 01718c63..39a0f086 100644
--- a/app/controllers/concerns/bbb_server.rb
+++ b/app/controllers/concerns/bbb_server.rb
@@ -54,7 +54,7 @@ module BbbServer
     join_opts = {}
     join_opts[:userID] = uid if uid
     join_opts[:join_via_html5] = true
-    join_opts[:createTime] = room.last_session.to_datetime.strftime("%Q")
+    join_opts[:createTime] = room.last_session.to_datetime.strftime("%Q") if room.last_session
 
     bbb_server.join_meeting_url(room.bbb_id, name, password, join_opts)
   end