diff --git a/src/server/api/endpoints/games/reversi/games/surrender.ts b/src/server/api/endpoints/games/reversi/games/surrender.ts
index dc9908aef..49821650e 100644
--- a/src/server/api/endpoints/games/reversi/games/surrender.ts
+++ b/src/server/api/endpoints/games/reversi/games/surrender.ts
@@ -12,7 +12,7 @@ export const meta = {
 	requireCredential: true,
 
 	params: {
-		gameId: $.type(ID).optional.note({
+		gameId: $.type(ID).note({
 			desc: {
 				ja: '投了したい対局'
 			}