diff --git a/packages/backend/src/server/api/mastodon/MastodonConverters.ts b/packages/backend/src/server/api/mastodon/MastodonConverters.ts
index e5d732ed79..cf625d6e94 100644
--- a/packages/backend/src/server/api/mastodon/MastodonConverters.ts
+++ b/packages/backend/src/server/api/mastodon/MastodonConverters.ts
@@ -4,7 +4,7 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { Entity } from 'megalodon';
+import { Entity, MastodonEntity } from 'megalodon';
 import mfm from '@transfem-org/sfm-js';
 import { MastodonNotificationType } from 'megalodon/lib/src/mastodon/notification.js';
 import { NotificationType } from 'megalodon/lib/src/notification.js';
@@ -275,7 +275,7 @@ export class MastodonConverters {
 			this.getUser(p)
 				.then(u => this.encode(u, mentionedRemoteUsers))
 				.catch(() => null)))
-			.then(p => p.filter(m => m)) as Promise<Entity.Mention[]>;
+			.then((p: Entity.Mention[]) => p.filter(m => m));
 
 		const tags = note.tags.map(tag => {
 			return {
@@ -327,7 +327,7 @@ export class MastodonConverters {
 			sensitive: status.sensitive || !!cw,
 			spoiler_text: cw,
 			visibility: status.visibility,
-			media_attachments: status.media_attachments.map(a => convertAttachment(a)),
+			media_attachments: status.media_attachments.map((a: Entity.Account) => convertAttachment(a)),
 			mentions: mentions,
 			tags: tags,
 			card: null, //FIXME
@@ -345,7 +345,7 @@ export class MastodonConverters {
 	public async convertConversation(conversation: Entity.Conversation, me: MiLocalUser | null): Promise<MastodonEntity.Conversation> {
 		return {
 			id: conversation.id,
-			accounts: await Promise.all(conversation.accounts.map(a => this.convertAccount(a))),
+			accounts: await Promise.all(conversation.accounts.map((a: Entity.Account) => this.convertAccount(a))),
 			last_status: conversation.last_status ? await this.convertStatus(conversation.last_status, me) : null,
 			unread: conversation.unread,
 		};
diff --git a/packages/backend/src/server/api/mastodon/endpoints/notifications.ts b/packages/backend/src/server/api/mastodon/endpoints/notifications.ts
index c3108c8b3e..ee6c990fd1 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/notifications.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/notifications.ts
@@ -4,6 +4,7 @@
  */
 
 import { Injectable } from '@nestjs/common';
+import { MastodonEntity } from 'megalodon';
 import { parseTimelineArgs, TimelineArgs } from '@/server/api/mastodon/argsUtils.js';
 import { MastodonConverters } from '@/server/api/mastodon/MastodonConverters.js';
 import { attachMinMaxPagination } from '@/server/api/mastodon/pagination.js';
diff --git a/packages/backend/src/server/api/mastodon/endpoints/search.ts b/packages/backend/src/server/api/mastodon/endpoints/search.ts
index 796f4cd5f7..78672639e5 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/search.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/search.ts
@@ -9,9 +9,8 @@ import { attachMinMaxPagination, attachOffsetPagination } from '@/server/api/mas
 import { MastodonConverters } from '../MastodonConverters.js';
 import { parseTimelineArgs, TimelineArgs, toBoolean, toInt } from '../argsUtils.js';
 import { ApiError } from '../../error.js';
-import Account = Entity.Account;
-import Status = Entity.Status;
 import type { FastifyInstance } from 'fastify';
+import type { Entity } from 'megalodon';
 
 interface ApiSearchMastodonRoute {
 	Querystring: TimelineArgs & {
@@ -53,8 +52,8 @@ export class ApiSearchMastodon {
 			const { data } = await client.search(request.query.q, { type, ...query });
 			const response = {
 				...data,
-				accounts: await Promise.all(data.accounts.map((account: Account) => this.mastoConverters.convertAccount(account))),
-				statuses: await Promise.all(data.statuses.map((status: Status) => this.mastoConverters.convertStatus(status, me))),
+				accounts: await Promise.all(data.accounts.map((account: Entity.Account) => this.mastoConverters.convertAccount(account))),
+				statuses: await Promise.all(data.statuses.map((status: Entity.Status) => this.mastoConverters.convertStatus(status, me))),
 			};
 
 			if (type === 'hashtags') {
@@ -90,8 +89,8 @@ export class ApiSearchMastodon {
 			const stat = !type || type === 'statuses' ? await client.search(request.query.q, { type: 'statuses', ...query }) : null;
 			const tags = !type || type === 'hashtags' ? await client.search(request.query.q, { type: 'hashtags', ...query }) : null;
 			const response = {
-				accounts: await Promise.all(acct?.data.accounts.map((account: Account) => this.mastoConverters.convertAccount(account)) ?? []),
-				statuses: await Promise.all(stat?.data.statuses.map((status: Status) => this.mastoConverters.convertStatus(status, me)) ?? []),
+				accounts: await Promise.all(acct?.data.accounts.map((account: Entity.Account) => this.mastoConverters.convertAccount(account)) ?? []),
+				statuses: await Promise.all(stat?.data.statuses.map((status: Entity.Status) => this.mastoConverters.convertStatus(status, me)) ?? []),
 				hashtags: tags?.data.hashtags ?? [],
 			};
 
@@ -113,7 +112,7 @@ export class ApiSearchMastodon {
 				{
 					method: 'POST',
 					headers: {
-						...request.headers as HeadersInit,
+						...request.headers,
 						'Accept': 'application/json',
 						'Content-Type': 'application/json',
 					},
@@ -122,7 +121,7 @@ export class ApiSearchMastodon {
 
 			await verifyResponse(res);
 
-			const data = await res.json() as Status[];
+			const data = await res.json() as Entity.Status[];
 			const me = await this.clientService.getAuth(request);
 			const response = await Promise.all(data.map(status => this.mastoConverters.convertStatus(status, me)));
 
@@ -136,7 +135,7 @@ export class ApiSearchMastodon {
 				{
 					method: 'POST',
 					headers: {
-						...request.headers as HeadersInit,
+						...request.headers,
 						'Accept': 'application/json',
 						'Content-Type': 'application/json',
 					},
@@ -150,7 +149,7 @@ export class ApiSearchMastodon {
 
 			await verifyResponse(res);
 
-			const data = await res.json() as Account[];
+			const data = await res.json() as Entity.Account[];
 			const response = await Promise.all(data.map(async entry => {
 				return {
 					source: 'global',
diff --git a/packages/backend/src/server/api/mastodon/endpoints/status.ts b/packages/backend/src/server/api/mastodon/endpoints/status.ts
index 39c4f44755..ec31e0cc46 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/status.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/status.ts
@@ -55,8 +55,8 @@ export class ApiStatusMastodon {
 
 			const { client, me } = await this.clientService.getAuthClient(_request);
 			const { data } = await client.getStatusContext(_request.params.id, parseTimelineArgs(_request.query));
-			const ancestors = await Promise.all(data.ancestors.map(async status => await this.mastoConverters.convertStatus(status, me)));
-			const descendants = await Promise.all(data.descendants.map(async status => await this.mastoConverters.convertStatus(status, me)));
+			const ancestors = await Promise.all(data.ancestors.map(async (status: Entity.Status) => await this.mastoConverters.convertStatus(status, me)));
+			const descendants = await Promise.all(data.descendants.map(async (status: Entity.Status) => await this.mastoConverters.convertStatus(status, me)));
 			const response = { ancestors, descendants };
 
 			reply.send(response);
@@ -166,7 +166,7 @@ export class ApiStatusMastodon {
 			if (body.in_reply_to_id && removed === '/unreact') {
 				const id = body.in_reply_to_id;
 				const post = await client.getStatus(id);
-				const react = post.data.emoji_reactions.filter(e => e.me)[0].name;
+				const react = post.data.emoji_reactions.filter((e: Entity.Emoji) => e.me)[0].name;
 				const data = await client.deleteEmojiReaction(id, react);
 				reply.send(data.data);
 			}