diff --git a/CHANGELOG_YOJO.md b/CHANGELOG_YOJO.md
index de5eb8736b..cbf9136d5e 100644
--- a/CHANGELOG_YOJO.md
+++ b/CHANGELOG_YOJO.md
@@ -45,7 +45,8 @@ Cherrypick 4.11.1
 - Change: `notes/advanced-search`で`query`が必須ではなくなりました
 - Fix: (Opensearch利用時)高度な検索でリプライ除外にするとエラーがでる
 - Fix: ノート編集時に3001文字以上の場合編集できない問題を修正
- 
+- Fix: 通知APIがページ境界で重複する問題の修正
+
 ### Misc
 
 ## 1.0.1
diff --git a/packages/backend/src/server/api/endpoints/i/notifications-grouped.ts b/packages/backend/src/server/api/endpoints/i/notifications-grouped.ts
index 833a74fe12..9bf5f0d0b2 100644
--- a/packages/backend/src/server/api/endpoints/i/notifications-grouped.ts
+++ b/packages/backend/src/server/api/endpoints/i/notifications-grouped.ts
@@ -97,7 +97,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				return [];
 			}
 
-			let notifications = notificationsRes.map(x => JSON.parse(x[1][1])).filter(x => x.id !== ps.untilId && x !== ps.sinceId) as MiNotification[];
+			let notifications = notificationsRes.map(x => JSON.parse(x[1][1])).filter(x => x.id !== ps.untilId && x.id !== ps.sinceId) as MiNotification[];
 
 			if (includeTypes && includeTypes.length > 0) {
 				notifications = notifications.filter(notification => includeTypes.includes(notification.type));
diff --git a/packages/backend/src/server/api/endpoints/i/notifications.ts b/packages/backend/src/server/api/endpoints/i/notifications.ts
index 2f619380e9..7bfc0ee3a1 100644
--- a/packages/backend/src/server/api/endpoints/i/notifications.ts
+++ b/packages/backend/src/server/api/endpoints/i/notifications.ts
@@ -110,7 +110,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					return [];
 				}
 
-				notifications = notificationsRes.map(x => JSON.parse(x[1][1])) as MiNotification[];
+				notifications = notificationsRes.map(x => JSON.parse(x[1][1])).filter(x => x.id !== ps.untilId && x.id !== ps.sinceId) as MiNotification[];
 
 				if (includeTypes && includeTypes.length > 0) {
 					notifications = notifications.filter(notification => includeTypes.includes(notification.type));