diff --git a/packages/backend/src/server/api/mastodon/converters/note.ts b/packages/backend/src/server/api/mastodon/converters/note.ts
index 60be5f749..70734f76f 100644
--- a/packages/backend/src/server/api/mastodon/converters/note.ts
+++ b/packages/backend/src/server/api/mastodon/converters/note.ts
@@ -17,11 +17,11 @@ import { populatePoll } from "@/models/repositories/note.js";
 import { FileConverter } from "@/server/api/mastodon/converters/file.js";
 
 export class NoteConverter {
-    public static async encode(note: Note, user?: ILocalUser): Promise<MastodonEntity.Status> {
+    public static async encode(note: Note, user: ILocalUser | null): Promise<MastodonEntity.Status> {
         const noteUser = note.user ?? await getUser(note.userId);
 
 				if (!await Notes.isVisibleForMe(note, user?.id ?? null))
-					throw new Error();
+					throw new Error('Cannot encode note not visible for user');
 
 				const host = note.user?.host ?? null;
 
@@ -49,7 +49,7 @@ export class NoteConverter {
 					}
 				}) : null;
 
-				const reply = note.reply ?? (note.replyId ? await getNote(note.replyId, user ?? null) : null);
+				const reply = note.reply ?? (note.replyId ? await getNote(note.replyId, user) : null);
 
 				const isBookmarked = user ? await NoteFavorites.exist({
 					where: {
@@ -109,7 +109,7 @@ export class NoteConverter {
         };
     }
 
-	public static async encodeMany(notes: Note[], user?: ILocalUser): Promise<MastodonEntity.Status[]> {
+	public static async encodeMany(notes: Note[], user: ILocalUser | null): Promise<MastodonEntity.Status[]> {
 		const encoded = notes.map(n => this.encode(n, user));
 		return Promise.all(encoded);
 	}
diff --git a/packages/backend/src/server/api/mastodon/endpoints/status.ts b/packages/backend/src/server/api/mastodon/endpoints/status.ts
index 82cb82209..750ad1a7e 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/status.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/status.ts
@@ -148,7 +148,7 @@ export function apiStatusMastodon(router: Router): void {
 	router.get<{ Params: { id: string } }>("/v1/statuses/:id", async (ctx) => {
 		try {
 			const auth = await authenticate(ctx.headers.authorization, null);
-			const user = auth[0] ?? undefined;
+			const user = auth[0] ?? null;
 
 			const noteId = convertId(ctx.params.id, IdType.IceshrimpId);
 			const note = await getNote(noteId, user ?? null).then(n => n).catch(() => null);
@@ -195,7 +195,7 @@ export function apiStatusMastodon(router: Router): void {
 			const accessTokens = ctx.headers.authorization;
 			try {
 				const auth = await authenticate(ctx.headers.authorization, null);
-				const user = auth[0] ?? undefined;
+				const user = auth[0] ?? null;
 
 				const id = convertId(ctx.params.id, IdType.IceshrimpId);
 				const note = await getNote(id, user ?? null).then(n => n).catch(() => null);
@@ -207,10 +207,10 @@ export function apiStatusMastodon(router: Router): void {
 				}
 
 				const ancestors = await NoteHelpers.getNoteAncestors(note, user, user ? 4096 : 60)
-					.then(n => NoteConverter.encodeMany(n))
+					.then(n => NoteConverter.encodeMany(n, user))
 					.then(n => n.map(s => convertStatus(s)));
 				const descendants = await NoteHelpers.getNoteDescendants(note, user, user ? 4096 : 40, user ? 4096 : 20)
-					.then(n => NoteConverter.encodeMany(n))
+					.then(n => NoteConverter.encodeMany(n, user))
 					.then(n => n.map(s => convertStatus(s)));
 
 				ctx.body = {
diff --git a/packages/backend/src/server/api/mastodon/helpers/note.ts b/packages/backend/src/server/api/mastodon/helpers/note.ts
index 0088857cd..0ee6d9c75 100644
--- a/packages/backend/src/server/api/mastodon/helpers/note.ts
+++ b/packages/backend/src/server/api/mastodon/helpers/note.ts
@@ -9,7 +9,7 @@ import querystring from "node:querystring";
 import { getNote } from "@/server/api/common/getters.js";
 
 export class NoteHelpers {
-	public static async getNoteDescendants(note: Note | string, user?: ILocalUser, limit: number = 10, depth: number = 2): Promise<Note[]> {
+	public static async getNoteDescendants(note: Note | string, user: ILocalUser | null, limit: number = 10, depth: number = 2): Promise<Note[]> {
 		const noteId = typeof note === "string" ? note : note.id;
 		const query = makePaginationQuery(Notes.createQueryBuilder("note"))
 			.andWhere(
@@ -29,16 +29,16 @@ export class NoteHelpers {
 		return query.getMany();
 	}
 
-	public static async getNoteAncestors(rootNote: Note, user?: ILocalUser, limit: number = 10): Promise<Note[]> {
+	public static async getNoteAncestors(rootNote: Note, user: ILocalUser | null, limit: number = 10): Promise<Note[]> {
 		const notes = new Array<Note>;
 		for (let i = 0; i < limit; i++) {
 			const currentNote = notes.at(-1) ?? rootNote;
 			if (!currentNote.replyId) break;
-			const nextNote = await getNote(currentNote.replyId, user ?? null).catch((e) => {
+			const nextNote = await getNote(currentNote.replyId, user).catch((e) => {
 				if (e.id === "9725d0ce-ba28-4dde-95a7-2cbb2c15de24") return null;
 				throw e;
 			});
-			if (nextNote) notes.push(nextNote);
+			if (nextNote && await Notes.isVisibleForMe(nextNote, user?.id ?? null)) notes.push(nextNote);
 			else break;
 		}