diff --git a/examples/io-descriptors/requirements.txt b/examples/io-descriptors/requirements.txt
index 555c292612..3f2b5da9ae 100644
--- a/examples/io-descriptors/requirements.txt
+++ b/examples/io-descriptors/requirements.txt
@@ -1,8 +1,5 @@
-diffusers
 bentoml
-transformers
 torch
-accelerate
 pydub
 pdf2img
 pandas
diff --git a/examples/io-descriptors/service.py b/examples/io-descriptors/service.py
index 0790366c4e..5fe2b430bf 100644
--- a/examples/io-descriptors/service.py
+++ b/examples/io-descriptors/service.py
@@ -48,9 +48,9 @@ def append_string_to_eof(
         txt_file: t.Annotated[Path, bentoml.validators.ContentType("text/plain")],
         input_string: str,
     ) -> t.Annotated[Path, bentoml.validators.ContentType("text/plain")]:
-        with open(output_path, "a") as file:
+        with open(txt_file, "a") as file:
             file.write(input_string)
-        return output_path
+        return txt_file
 
 
 @bentoml.service()