diff --git a/packages/backend/src/server/api/mastodon/endpoints/filter.ts b/packages/backend/src/server/api/mastodon/endpoints/filter.ts
index 069d0044e..b57adb30a 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/filter.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/filter.ts
@@ -1,5 +1,6 @@
 import Router from "@koa/router";
 import { auth } from "@/server/api/mastodon/middleware/auth.js";
+import { MastoApiError } from "@/server/api/mastodon/middleware/catch-errors.js";
 
 export function setupEndpointsFilter(router: Router): void {
     router.get(["/v1/filters", "/v2/filters"],
@@ -11,8 +12,7 @@ export function setupEndpointsFilter(router: Router): void {
     router.post(["/v1/filters", "/v2/filters"],
         auth(true, ['write:filters']),
         async (ctx) => {
-            ctx.status = 400;
-            ctx.body = { error: "Please change word mute settings in the web frontend settings." };
+            throw new MastoApiError(400, "Please change word mute settings in the web frontend settings.");
         }
     );
 }
diff --git a/packages/backend/src/server/api/mastodon/endpoints/status.ts b/packages/backend/src/server/api/mastodon/endpoints/status.ts
index 2b25bdb23..8cc8927e4 100644
--- a/packages/backend/src/server/api/mastodon/endpoints/status.ts
+++ b/packages/backend/src/server/api/mastodon/endpoints/status.ts
@@ -15,6 +15,7 @@ import { UserConverter } from "@/server/api/mastodon/converters/user.js";
 import { PollHelpers } from "@/server/api/mastodon/helpers/poll.js";
 import { toArray } from "@/prelude/array.js";
 import { auth } from "@/server/api/mastodon/middleware/auth.js";
+import { MastoApiError } from "@/server/api/mastodon/middleware/catch-errors.js";
 
 export function setupEndpointsStatus(router: Router): void {
     router.post("/v1/statuses",
@@ -280,11 +281,7 @@ export function setupEndpointsStatus(router: Router): void {
 
             const body: any = ctx.request.body;
             const choices = toArray(body.choices ?? []).map(p => parseInt(p));
-            if (choices.length < 1) {
-                ctx.status = 400;
-                ctx.body = { error: 'Must vote for at least one option' };
-                return;
-            }
+            if (choices.length < 1)  throw new MastoApiError(400, "Must vote for at least one option");
 
             const data = await PollHelpers.voteInPoll(choices, note, ctx.user, ctx.cache);
             ctx.body = convertPollId(data);
diff --git a/packages/backend/src/server/api/mastodon/middleware/auth.ts b/packages/backend/src/server/api/mastodon/middleware/auth.ts
index 152dfb73a..c656d9f7a 100644
--- a/packages/backend/src/server/api/mastodon/middleware/auth.ts
+++ b/packages/backend/src/server/api/mastodon/middleware/auth.ts
@@ -2,6 +2,7 @@ import authenticate from "@/server/api/authenticate.js";
 import { ILocalUser } from "@/models/entities/user.js";
 import { MastoContext } from "@/server/api/mastodon/index.js";
 import { AuthConverter } from "@/server/api/mastodon/converters/auth.js";
+import { MastoApiError } from "@/server/api/mastodon/middleware/catch-errors.js";
 
 export async function AuthMiddleware(ctx: MastoContext, next: () => Promise<any>) {
     const auth = await authenticate(ctx.headers.authorization, null, true);
@@ -13,20 +14,13 @@ export async function AuthMiddleware(ctx: MastoContext, next: () => Promise<any>
 
 export function auth(required: boolean, scopes: string[] = []) {
     return async function auth(ctx: MastoContext, next: () => Promise<any>) {
-        if (required && !ctx.user) {
-            ctx.status = 401;
-            ctx.body = { error: "This method requires an authenticated user" };
-            return;
-        }
+        if (required && !ctx.user) throw new MastoApiError(401, "This method requires an authenticated user");
 
         if (!AuthConverter.decode(scopes).every(p => ctx.scopes.includes(p))) {
-            if (required) {
-                ctx.status = 403;
-                ctx.body = { error: "This action is outside the authorized scopes" };
-            } else {
-                ctx.user = null;
-                ctx.scopes = [];
-            }
+            if (required) throw new MastoApiError(403, "This action is outside the authorized scopes")
+
+            ctx.user = null;
+            ctx.scopes = [];
         }
 
         ctx.scopes = AuthConverter.encode(ctx.scopes);