diff --git a/packages/backend/test-federation/compose.tpl.yml b/packages/backend/test-federation/compose.tpl.yml
index 25770063d3..33e75841c0 100644
--- a/packages/backend/test-federation/compose.tpl.yml
+++ b/packages/backend/test-federation/compose.tpl.yml
@@ -50,6 +50,14 @@ services:
         source: ../../misskey-js/package.json
         target: /misskey/packages/misskey-js/package.json
         read_only: true
+      - type: bind
+        source: ../../misskey-mahjong/built
+        target: /misskey/packages/misskey-mahjong/built
+        read_only: true
+      - type: bind
+        source: ../../misskey-mahjong/package.json
+        target: /misskey/packages/misskey-mahjong/package.json
+        read_only: true
       - type: bind
         source: ../../misskey-reversi/built
         target: /misskey/packages/misskey-reversi/built