diff --git a/bun.lock b/bun.lock
index 21e377b..9536e3f 100644
--- a/bun.lock
+++ b/bun.lock
@@ -7,7 +7,6 @@
         "@aws-sdk/client-polly": "^3.823.0",
         "@hono/node-server": "^1.14.3",
         "ffmpeg-static": "^5.2.0",
-        "fluent-ffmpeg": "^2.1.3",
         "hono": "^4.7.11",
         "openai": "^4.104.0",
         "react": "^19.1.0",
@@ -333,8 +332,6 @@
 
     "agentkeepalive": ["agentkeepalive@4.6.0", "", { "dependencies": { "humanize-ms": "^1.2.1" } }, "sha512-kja8j7PjmncONqaTsB8fQ+wE2mSU2DJ9D4XKoJ5PFWIdRMa6SLSN1ff4mOr4jCbfRSsxR4keIiySJU0N9T5hIQ=="],
 
-    "async": ["async@0.2.10", "", {}, "sha512-eAkdoKxU6/LkKDBzLpT+t6Ff5EtfSF4wx1WfJiPEEV7WNLnDaRXk0oVysiEPm262roaachGexwUv94WhSgN5TQ=="],
-
     "asynckit": ["asynckit@0.4.0", "", {}, "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q=="],
 
     "bowser": ["bowser@2.11.0", "", {}, "sha512-AlcaJBi/pqqJBIQ8U9Mcpc9i8Aqxn88Skv5d+xBX006BY5u8N3mGLHa5Lgppa7L/HfwgwLgZ6NYs+Ag6uUmJRA=="],
@@ -391,8 +388,6 @@
 
     "ffmpeg-static": ["ffmpeg-static@5.2.0", "", { "dependencies": { "@derhuerst/http-basic": "^8.2.0", "env-paths": "^2.2.0", "https-proxy-agent": "^5.0.0", "progress": "^2.0.3" } }, "sha512-WrM7kLW+do9HLr+H6tk7LzQ7kPqbAgLjdzNE32+u3Ff11gXt9Kkkd2nusGFrlWMIe+XaA97t+I8JS7sZIrvRgA=="],
 
-    "fluent-ffmpeg": ["fluent-ffmpeg@2.1.3", "", { "dependencies": { "async": "^0.2.9", "which": "^1.1.1" } }, "sha512-Be3narBNt2s6bsaqP6Jzq91heDgOEaDCJAXcE3qcma/EJBSy5FB4cvO31XBInuAuKBx8Kptf8dkhjK0IOru39Q=="],
-
     "form-data": ["form-data@4.0.2", "", { "dependencies": { "asynckit": "^0.4.0", "combined-stream": "^1.0.8", "es-set-tostringtag": "^2.1.0", "mime-types": "^2.1.12" } }, "sha512-hGfm/slu0ZabnNt4oaRZ6uREyfCj6P4fT/n6A1rGV+Z0VdGXjfOhVUpkn6qVQONHGIFwmveGXyDs75+nr6FM8w=="],
 
     "form-data-encoder": ["form-data-encoder@1.7.2", "", {}, "sha512-qfqtYan3rxrnCk1VYaA4H+Ms9xdpPqvLZa6xmMgFvhO32x7/3J/ExcTd6qpxM0vH2GdMI+poehyBZvqfMTto8A=="],
@@ -429,8 +424,6 @@
 
     "inherits": ["inherits@2.0.4", "", {}, "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="],
 
-    "isexe": ["isexe@2.0.0", "", {}, "sha512-RHxMLp9lnKHGHRng9QFhRCMbYAcVpn69smSGcq3f36xjgVVWThj4qqLbTLlq7Ssj8B+fIQ1EuCEGI2lKsyQeIw=="],
-
     "js-tokens": ["js-tokens@4.0.0", "", {}, "sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ=="],
 
     "jsesc": ["jsesc@3.1.0", "", { "bin": { "jsesc": "bin/jsesc" } }, "sha512-/sM3dO2FOzXjKQhJuo0Q173wf2KOo8t4I8vHy6lF9poUp7bKT0/NHE8fPX23PwfhnykfqnC2xRxOnVw5XuGIaA=="],
@@ -519,8 +512,6 @@
 
     "whatwg-url": ["whatwg-url@5.0.0", "", { "dependencies": { "tr46": "~0.0.3", "webidl-conversions": "^3.0.0" } }, "sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw=="],
 
-    "which": ["which@1.3.1", "", { "dependencies": { "isexe": "^2.0.0" }, "bin": { "which": "./bin/which" } }, "sha512-HxJdYWq1MTIQbJ3nw0cqssHoTNU267KlrDuGZ1WYlxDStUtKUhOaJmh112/TZmHxxUfuJqPXSOm7tDyas0OSIQ=="],
-
     "xml2js": ["xml2js@0.5.0", "", { "dependencies": { "sax": ">=0.6.0", "xmlbuilder": "~11.0.0" } }, "sha512-drPFnkQJik/O+uPKpqSgr22mpuFHqKdbS835iAQrUC73L2F5WkboIRd63ai/2Yg6I1jzifPFKH2NTK+cfglkIA=="],
 
     "xmlbuilder": ["xmlbuilder@11.0.1", "", {}, "sha512-fDlsI/kFEx7gLvbecc0/ohLG50fugQp8ryHzMTuW9vSa1GJ0XYWKnhsUx7oie3G98+r56aTQIUB4kht42R3JvA=="],
diff --git a/package.json b/package.json
index a9112ed..3081baf 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,6 @@
     "@aws-sdk/client-polly": "^3.823.0",
     "@hono/node-server": "^1.14.3",
     "ffmpeg-static": "^5.2.0",
-    "fluent-ffmpeg": "^2.1.3",
     "hono": "^4.7.11",
     "openai": "^4.104.0",
     "react": "^19.1.0",
diff --git a/services/tts.ts b/services/tts.ts
index cb8e8f5..0615070 100644
--- a/services/tts.ts
+++ b/services/tts.ts
@@ -1,6 +1,6 @@
 import fs from "fs";
 import path from "path";
-import ffmpeg from "fluent-static";
+import ffmpegPath from "ffmpeg-static";
 
 // VOICEVOX APIの設定
 const VOICEVOX_HOST = import.meta.env["VOICEVOX_HOST"];
@@ -72,7 +72,7 @@ export async function generateTTS(
   console.log(`MP3変換開始: ${wavFilePath} -> ${mp3FilePath}`);
   Bun.spawnSync({
     cmd: [
-      ffmpeg,
+      ffmpegPath || "ffmpeg",
       "-i",
       wavFilePath,
       "-codec:a",