diff --git a/chattts/bentofile.yaml b/chattts/bentofile.yaml
index dc082756..843e8bca 100644
--- a/chattts/bentofile.yaml
+++ b/chattts/bentofile.yaml
@@ -8,6 +8,9 @@ include:
 python:
   requirements_txt: "./requirements.txt"
   lock_packages: true
+docker:
+  system_packages:
+    - libsox-dev
 envs:
   - name: CHAT_TTS_REPO
     value: https://github.com/2noise/ChatTTS.git
diff --git a/chattts/service.py b/chattts/service.py
index 67e5d279..74d765a6 100644
--- a/chattts/service.py
+++ b/chattts/service.py
@@ -4,6 +4,7 @@ from typing import Annotated
 import sys
 import shutil
 import io
+import pathlib
 
 import bentoml
 from bentoml.validators import ContentType
@@ -46,7 +47,7 @@ class Main:
         self.chat.load_models(compile=False) # Set to True for better performance
 
     @bentoml.api
-    def tts(self, text: str = "PUT YOUR TEXT HERE") -> Annotated[bytes, ContentType("audio/wav")]:
+    def tts(self, text: str = "PUT YOUR TEXT HERE") -> Annotated[pathlib.Path, ContentType("audio/wav")]:
         import torch
         import torchaudio