diff --git a/CHANGELOG.md b/CHANGELOG.md
index 31dfb6ce1199..9ff5881df069 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@
 
 ### Server
 - Fix: nodeinfoにenableMcaptchaとenableTurnstileが無いのを修正
+- エンドポイント`flash/update`の`flashId`以外のパラメータは必須ではなくなりました
 - Fix: 禁止キーワードを含むノートがDelayed Queueに追加されて再処理される問題を修正
 
 ## 2024.2.0
diff --git a/packages/backend/src/server/api/endpoints/flash/update.ts b/packages/backend/src/server/api/endpoints/flash/update.ts
index 7d7633daa527..e378669f0a6e 100644
--- a/packages/backend/src/server/api/endpoints/flash/update.ts
+++ b/packages/backend/src/server/api/endpoints/flash/update.ts
@@ -51,7 +51,7 @@ export const paramDef = {
 		} },
 		visibility: { type: 'string', enum: ['public', 'private'] },
 	},
-	required: ['flashId', 'title', 'summary', 'script', 'permissions'],
+	required: ['flashId'],
 } as const;
 
 @Injectable()
@@ -71,11 +71,11 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 			await this.flashsRepository.update(flash.id, {
 				updatedAt: new Date(),
-				title: ps.title,
-				summary: ps.summary,
-				script: ps.script,
-				permissions: ps.permissions,
-				visibility: ps.visibility,
+				...Object.fromEntries(
+					Object.entries(ps).filter(
+						([key, val]) => (key !== 'flashId') && Object.hasOwn(paramDef.properties, key)
+					)
+				),
 			});
 		});
 	}
diff --git a/packages/misskey-js/src/autogen/types.ts b/packages/misskey-js/src/autogen/types.ts
index 9bf79fde7199..0b2a88b53787 100644
--- a/packages/misskey-js/src/autogen/types.ts
+++ b/packages/misskey-js/src/autogen/types.ts
@@ -22927,10 +22927,10 @@ export type operations = {
         'application/json': {
           /** Format: misskey:id */
           flashId: string;
-          title: string;
-          summary: string;
-          script: string;
-          permissions: string[];
+          title?: string;
+          summary?: string;
+          script?: string;
+          permissions?: string[];
           /** @enum {string} */
           visibility?: 'public' | 'private';
         };