diff --git a/doc/lua_api.md b/doc/lua_api.md
index 07f70c36f..5a2e16707 100644
--- a/doc/lua_api.md
+++ b/doc/lua_api.md
@@ -6839,6 +6839,7 @@ You can find mod channels communication scheme in `doc/mod_channels.png`.
     * Server joins channel `channel_name`, and creates it if necessary. You
       should listen for incoming messages with
       `core.register_on_modchannel_message`
+    * This returns a [ModChannel] object.
 
 Inventory
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