diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2157ce35d734..f161748b7ca4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@
 ### Client
 
 ### Server
+- Fix: includeSensitiveChannelがfunout timelineの範囲では機能しない問題
 
 ## 2023.11.1-kinel.2
 
diff --git a/packages/backend/src/server/api/endpoints/users/notes.ts b/packages/backend/src/server/api/endpoints/users/notes.ts
index 671af8a870b0..5daa5bce18a3 100644
--- a/packages/backend/src/server/api/endpoints/users/notes.ts
+++ b/packages/backend/src/server/api/endpoints/users/notes.ts
@@ -53,7 +53,7 @@ export const paramDef = {
 		untilDate: { type: 'integer' },
 		withFiles: { type: 'boolean', default: false },
 		excludeNsfw: { type: 'boolean', default: false },
-		includeSensitiveChannel: { type: 'boolean', default: false },
+		includeSensitiveChannel: { type: 'boolean' },
 	},
 	required: ['userId'],
 } as const;
@@ -78,6 +78,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			const sinceId = ps.sinceId ?? (ps.sinceDate ? this.idService.gen(ps.sinceDate!) : null);
 			const isRangeSpecified = untilId != null && sinceId != null;
 			const isSelf = me && (me.id === ps.userId);
+			const includeSensitiveChannel = ps.includeSensitiveChannel ?? isSelf;
 
 			if (isRangeSpecified || sinceId == null) {
 				const [
@@ -123,7 +124,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 							}
 						}
 
-						if (note.channel?.isSensitive && !isSelf) return false;
+						if (note.channel?.isSensitive && !includeSensitiveChannel) return false;
 						if (note.visibility === 'specified' && (!me || (me.id !== note.userId && !note.visibleUserIds.some(v => v === me.id)))) return false;
 						if (note.visibility === 'followers' && !isFollowing && !isSelf) return false;
 
@@ -151,7 +152,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				.leftJoinAndSelect('renote.user', 'renoteUser');
 
 			if (ps.withChannelNotes) {
-				if (!ps.includeSensitiveChannel) query.andWhere(new Brackets(qb => {
+				if (!includeSensitiveChannel) query.andWhere(new Brackets(qb => {
 					qb.orWhere('note.channelId IS NULL');
 					qb.orWhere('channel.isSensitive = false');
 				}));
diff --git a/packages/backend/test/e2e/timelines.ts b/packages/backend/test/e2e/timelines.ts
index 73c446444be4..0954274ea933 100644
--- a/packages/backend/test/e2e/timelines.ts
+++ b/packages/backend/test/e2e/timelines.ts
@@ -1209,6 +1209,32 @@ describe('Timelines', () => {
 			assert.strictEqual(res.body.some((note: any) => note.id === bobNote.id), true);
 		});
 
+		test.concurrent('[withChannelNotes: true, includeSensitiveChannel: true] 他人が取得した場合もセンシティブチャンネル投稿が含まれる', async () => {
+			const [alice, bob] = await Promise.all([signup(), signup()]);
+
+			const channel = await api('/channels/create', { name: 'channel', isSensitive: true }, bob).then(x => x.body);
+			const bobNote = await post(bob, { text: 'hi', channelId: channel.id });
+
+			await waitForPushToTl();
+
+			const res = await api('/users/notes', { userId: bob.id, withChannelNotes: true, includeSensitiveChannel: true }, alice);
+
+			assert.strictEqual(res.body.some((note: any) => note.id === bobNote.id), true);
+		});
+
+		test.concurrent('[withChannelNotes: true, includeSensitiveChannel: false] 自分が取得した場合もセンシティブチャンネル投稿が含まれない', async () => {
+			const [bob] = await Promise.all([signup()]);
+
+			const channel = await api('/channels/create', { name: 'channel', isSensitive: true }, bob).then(x => x.body);
+			const bobNote = await post(bob, { text: 'hi', channelId: channel.id });
+
+			await waitForPushToTl();
+
+			const res = await api('/users/notes', { userId: bob.id, withChannelNotes: true, includeSensitiveChannel: false }, bob);
+
+			assert.strictEqual(res.body.some((note: any) => note.id === bobNote.id), false);
+		});
+
 		test.concurrent('ミュートしているユーザーに関連する投稿が含まれない', async () => {
 			const [alice, bob, carol] = await Promise.all([signup(), signup(), signup()]);