diff --git a/CHANGELOG.md b/CHANGELOG.md
index d58ff7691f..64b47883d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@ You should also include the user name that made the change.
 - Server: 引用内の文章がnyaizeされてしまう問題を修正 @kabo2468
 - Server: Bug fix for Pinned Users lookup on instance @squidicuzz
 - Server: Fix peers API returning suspended instances @ineffyble
+- Server: trim long text of note from ap @syuilo
 - Client: case insensitive emoji search @saschanaz
 - Client: InAppウィンドウが操作できなくなることがあるのを修正 @tamaina
 - Client: use proxied image for instance icon @syuilo
diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index e9c2252314..cc6c213446 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -41,6 +41,7 @@ import { ApDeliverManagerService } from '@/core/activitypub/ApDeliverManagerServ
 import { NoteReadService } from '@/core/NoteReadService.js';
 import { RemoteUserResolveService } from '@/core/RemoteUserResolveService.js';
 import { bindThis } from '@/decorators.js';
+import { DB_MAX_NOTE_TEXT_LENGTH } from '@/const.js';
 
 const mutedWordsCache = new Cache<{ userId: UserProfile['userId']; mutedWords: UserProfile['mutedWords']; }[]>(1000 * 60 * 5);
 
@@ -259,6 +260,9 @@ export class NoteCreateService {
 		}
 
 		if (data.text) {
+			if (data.text.length > DB_MAX_NOTE_TEXT_LENGTH) {
+				data.text = data.text.slice(0, DB_MAX_NOTE_TEXT_LENGTH);
+			}
 			data.text = data.text.trim();
 		} else {
 			data.text = null;