diff --git a/built/file-info.js b/built/file-info.js
index ff1cc3d..a55f419 100644
--- a/built/file-info.js
+++ b/built/file-info.js
@@ -55,7 +55,7 @@ async function checkSvg(path) {
 import { FILE_TYPE_BROWSERSAFE } from './const.js';
 const dictionary = {
     'safe-file': FILE_TYPE_BROWSERSAFE,
-    'sharp-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng', 'image/webp', 'image/avif', 'image/svg+xml'],
-    'sharp-animation-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/avif', 'image/svg+xml'],
+    'sharp-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng', 'image/webp', 'image/avif', 'image/svg+xml', 'image/x-icon', 'image/bmp'],
+    'sharp-animation-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/avif', 'image/svg+xml', 'image/x-icon', 'image/bmp'],
 };
 export const isMimeImage = (mime, type) => dictionary[type].includes(mime);
diff --git a/built/index.js b/built/index.js
index a0a1305..df114ea 100644
--- a/built/index.js
+++ b/built/index.js
@@ -4,9 +4,10 @@ import { dirname } from 'node:path';
 import fastifyStatic from '@fastify/static';
 import { createTemp } from './create-temp.js';
 import { FILE_TYPE_BROWSERSAFE } from './const.js';
-import { convertToWebpStream, webpDefault } from './image-processor.js';
+import { convertToWebpStream, webpDefault, convertSharpToWebpStream } from './image-processor.js';
 import { detectType, isMimeImage } from './file-info.js';
 import sharp from 'sharp';
+import { sharpBmp } from 'sharp-read-bmp';
 import { StatusError } from './status-error.js';
 import { defaultDownloadConfig, downloadUrl } from './download.js';
 import { getAgents } from './http.js';
@@ -107,7 +108,7 @@ async function proxyHandler(request, reply) {
                 };
             }
             else {
-                const data = sharp(file.path, { animated: !('static' in request.query) })
+                const data = (await sharpBmp(file.path, file.mime, { animated: !('static' in request.query) }))
                     .resize({
                     height: 'emoji' in request.query ? 128 : 320,
                     withoutEnlargement: true,
@@ -121,13 +122,13 @@ async function proxyHandler(request, reply) {
             }
         }
         else if ('static' in request.query) {
-            image = convertToWebpStream(file.path, 498, 280);
+            image = convertSharpToWebpStream(await sharpBmp(file.path, file.mime), 498, 280);
         }
         else if ('preview' in request.query) {
-            image = convertToWebpStream(file.path, 200, 200);
+            image = convertSharpToWebpStream(await sharpBmp(file.path, file.mime), 200, 200);
         }
         else if ('badge' in request.query) {
-            const mask = sharp(file.path)
+            const mask = (await sharpBmp(file.path, file.mime))
                 .resize(96, 96, {
                 fit: 'inside',
                 withoutEnlargement: false,
diff --git a/package.json b/package.json
index 16fe28c..b274024 100644
--- a/package.json
+++ b/package.json
@@ -1,9 +1,9 @@
 {
   "name": "misskey-media-proxy",
-  "version": "0.0.16",
+  "version": "0.0.17",
   "description": "The Media Proxy for Misskey",
   "main": "built/index.js",
-  "packageManager": "pnpm@7.26.0",
+  "packageManager": "pnpm@7.28.0",
   "type": "module",
   "files": [
     "built",
@@ -47,6 +47,7 @@
     "is-svg": "^4.3.2",
     "private-ip": "^3.0.0",
     "sharp": "^0.31.3",
+    "sharp-read-bmp": "github:misskey-dev/sharp-read-bmp",
     "tmp": "^0.2.1"
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 700c683..70d9acc 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -19,6 +19,7 @@ specifiers:
   is-svg: ^4.3.2
   private-ip: ^3.0.0
   sharp: ^0.31.3
+  sharp-read-bmp: github:misskey-dev/sharp-read-bmp
   tmp: ^0.2.1
   typescript: ^4.9.5
 
@@ -35,6 +36,7 @@ dependencies:
   is-svg: 4.3.2
   private-ip: 3.0.0
   sharp: 0.31.3
+  sharp-read-bmp: github.com/misskey-dev/sharp-read-bmp/c5fb82e26fa50fca8b3b2d7e22467626d7f61baa
   tmp: 0.2.1
 
 devDependencies:
@@ -48,6 +50,10 @@ devDependencies:
 
 packages:
 
+  /@canvas/image-data/1.0.0:
+    resolution: {integrity: sha512-BxOqI5LgsIQP1odU5KMwV9yoijleOPzHL18/YvNqF9KFSGF2K/DLlYAbDQsWqd/1nbaFuSkYD/191dpMtNh4vw==}
+    dev: false
+
   /@chainsafe/is-ip/2.0.1:
     resolution: {integrity: sha512-nqSJ8u2a1Rv9FYbyI8qpDhTYujaKEyLknNrTejLYoSWmdeg+2WB7R6BZqPZYfrJzDxVi3rl6ZQuoaEvpKRZWgQ==}
     dev: false
@@ -643,6 +649,23 @@ packages:
       ms: 2.1.2
     dev: false
 
+  /decode-bmp/0.2.1:
+    resolution: {integrity: sha512-NiOaGe+GN0KJqi2STf24hfMkFitDUaIoUU3eKvP/wAbLe8o6FuW5n/x7MHPR0HKvBokp6MQY/j7w8lewEeVCIA==}
+    engines: {node: '>=8.6.0'}
+    dependencies:
+      '@canvas/image-data': 1.0.0
+      to-data-view: 1.1.0
+    dev: false
+
+  /decode-ico/0.4.1:
+    resolution: {integrity: sha512-69NZfbKIzux1vBOd31al3XnMnH+2mqDhEgLdpygErm4d60N+UwA5Sq5WFjmEDQzumgB9fElojGwWG0vybVfFmA==}
+    engines: {node: '>=8.6'}
+    dependencies:
+      '@canvas/image-data': 1.0.0
+      decode-bmp: 0.2.1
+      to-data-view: 1.1.0
+    dev: false
+
   /decompress-response/6.0.0:
     resolution: {integrity: sha512-aW35yZM6Bb/4oJlZncMH2LCoZtJXTRxES17vE3hoRiowU2kWHaJKFkSBDnDR+cm9J+9QhXmREyIfv0pji9ejCQ==}
     engines: {node: '>=10'}
@@ -1978,6 +2001,10 @@ packages:
     resolution: {integrity: sha512-3f0uOEAQwIqGuWW2MVzYg8fV/QNnc/IpuJNG837rLuczAaLVHslWHZQj4IGiEl5Hs3kkbhwL9Ab7Hrsmuj+Smw==}
     dev: false
 
+  /to-data-view/1.1.0:
+    resolution: {integrity: sha512-1eAdufMg6mwgmlojAx3QeMnzB/BTVp7Tbndi3U7ftcT2zCZadjxkkmLmd97zmaxWi+sgGcgWrokmpEoy0Dn0vQ==}
+    dev: false
+
   /to-regex-range/5.0.1:
     resolution: {integrity: sha512-65P7iz6X5yEr1cwcgvQxbbIw7Uk3gOy5dIdtZ4rDveLqhrdJP+Li/Hx6tyK0NEb+2GCyneCMJiGqrADCSNk8sQ==}
     engines: {node: '>=8.0'}
@@ -2064,3 +2091,13 @@ packages:
     resolution: {integrity: sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==}
     engines: {node: '>=10'}
     dev: false
+
+  github.com/misskey-dev/sharp-read-bmp/c5fb82e26fa50fca8b3b2d7e22467626d7f61baa:
+    resolution: {tarball: https://codeload.github.com/misskey-dev/sharp-read-bmp/tar.gz/c5fb82e26fa50fca8b3b2d7e22467626d7f61baa}
+    name: sharp-read-bmp
+    version: 1.0.0
+    dependencies:
+      decode-bmp: 0.2.1
+      decode-ico: 0.4.1
+      sharp: 0.31.3
+    dev: false
diff --git a/src/file-info.ts b/src/file-info.ts
index e5f888e..c14bdfd 100644
--- a/src/file-info.ts
+++ b/src/file-info.ts
@@ -66,8 +66,8 @@ import { FILE_TYPE_BROWSERSAFE } from './const.js';
 
 const dictionary = {
     'safe-file': FILE_TYPE_BROWSERSAFE,
-    'sharp-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng', 'image/webp', 'image/avif', 'image/svg+xml'],
-    'sharp-animation-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/avif', 'image/svg+xml'],
+    'sharp-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng', 'image/webp', 'image/avif', 'image/svg+xml', 'image/x-icon', 'image/bmp'],
+    'sharp-animation-convertible-image': ['image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/avif', 'image/svg+xml', 'image/x-icon', 'image/bmp'],
 };
 
 export const isMimeImage = (mime: string, type: keyof typeof dictionary): boolean => dictionary[type].includes(mime);
diff --git a/src/index.ts b/src/index.ts
index 2bb616e..0db33b3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -6,10 +6,11 @@ import { dirname } from 'node:path';
 import fastifyStatic from '@fastify/static';
 import { createTemp } from './create-temp.js';
 import { FILE_TYPE_BROWSERSAFE } from './const.js';
-import { IImageStreamable, convertToWebpStream, webpDefault } from './image-processor.js';
+import { IImageStreamable, convertToWebpStream, webpDefault, convertSharpToWebpStream } from './image-processor.js';
 import type { FastifyInstance, FastifyRequest, FastifyReply, FastifyPluginOptions } from 'fastify';
 import { detectType, isMimeImage } from './file-info.js';
 import sharp from 'sharp';
+import { sharpBmp } from 'sharp-read-bmp';
 import { StatusError } from './status-error.js';
 import { DownloadConfig, defaultDownloadConfig, downloadUrl } from './download.js';
 import { getAgents } from './http.js';
@@ -153,12 +154,12 @@ async function proxyHandler(request: FastifyRequest<{ Params: { url: string; };
                     type: file.mime,
                 };
             } else {
-                const data = sharp(file.path, { animated: !('static' in request.query) })
-                        .resize({
-                            height: 'emoji' in request.query ? 128 : 320,
-                            withoutEnlargement: true,
-                        })
-                        .webp(webpDefault);
+                const data = (await sharpBmp(file.path, file.mime, { animated: !('static' in request.query) }))
+                    .resize({
+                        height: 'emoji' in request.query ? 128 : 320,
+                        withoutEnlargement: true,
+                    })
+                    .webp(webpDefault);
 
                 image = {
                     data,
@@ -167,11 +168,11 @@ async function proxyHandler(request: FastifyRequest<{ Params: { url: string; };
                 };
             }
         } else if ('static' in request.query) {
-            image = convertToWebpStream(file.path, 498, 280);
+            image = convertSharpToWebpStream(await sharpBmp(file.path, file.mime), 498, 280);
         } else if ('preview' in request.query) {
-            image = convertToWebpStream(file.path, 200, 200);
+            image = convertSharpToWebpStream(await sharpBmp(file.path, file.mime), 200, 200);
         } else if ('badge' in request.query) {
-            const mask = sharp(file.path)
+            const mask = (await sharpBmp(file.path, file.mime))
                 .resize(96, 96, {
                     fit: 'inside',
                     withoutEnlargement: false,