diff --git a/auth_hybrid_matrix_token/mod_matrix_lobby_bypass.lua b/auth_hybrid_matrix_token/mod_matrix_lobby_bypass.lua
index dbc3267..7105646 100644
--- a/auth_hybrid_matrix_token/mod_matrix_lobby_bypass.lua
+++ b/auth_hybrid_matrix_token/mod_matrix_lobby_bypass.lua
@@ -29,6 +29,11 @@ module:hook("muc-occupant-pre-join", function (event)
         return
     end
 
+    if not event.origin.matrix_affiliation then
+        module:log(LOGLEVEL, "skip lobby_bypass, not a matrix user")
+        return
+    end
+
     local roomName, _ = jid_split(room.jid)
     local roomId = basexx.from_base32(roomName)
     if not roomId then