diff --git a/tests/test_get_reviewers_rest.py b/tests/test_get_reviewers_rest.py
index 3c9adff..1019e8f 100644
--- a/tests/test_get_reviewers_rest.py
+++ b/tests/test_get_reviewers_rest.py
@@ -1,40 +1,44 @@
 import json
 import os
-from typing import Callable, Any
+from pathlib import Path
+from typing import Callable
 from unittest.mock import patch
 
 import aiohttp
 import pytest
 from aioresponses import aioresponses
+
 from pr_reviews.queries.get_reviewers_rest import fetch
 
+
 @pytest.fixture
-def read_reviews_file():
+def read_reviews_file() -> str:
     # assume the reviews_response.json file is in the tests/fixtures directory
-    with open("tests/fixtures/reviews_response.json") as file:
-        return json.load(file)
+    with Path("tests/fixtures/reviews_response.json").open("r") as file:
+        return json.dumps(json.load(file))
 
 @pytest.fixture
-def get_reviews_url():
+def get_reviews_url() -> callable:
     def _get_reviews_url(owner: str, repo: str, pull_number: int) -> str:
-        url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{pull_number}/reviews"
-        return url
+        return f"https://api.github.com/repos/{owner}/{repo}/pulls/{pull_number}/reviews"
     return _get_reviews_url
 
 
 @pytest.fixture
-def mock_aioresponse():
+def mock_aioresponse() -> aioresponses:
     with aioresponses() as m:
         yield m
 
 @pytest.mark.asyncio
 @patch.dict(os.environ, {"GITHUB_TOKEN": "test_token"})
-async def test_get_reviewers_success(read_reviews_file, get_reviews_url, mock_aioresponse):
+async def test_get_reviewers_success(read_reviews_file: str,
+                                     get_reviews_url: Callable[[],str],
+                                     mock_aioresponse: aioresponses) -> None:
     url = get_reviews_url("expressjs", "express", 1)
     mock_aioresponse.get(
         url,
         status=200,
-        payload=read_reviews_file
+        payload=read_reviews_file,
     )
     async with aiohttp.ClientSession() as client:
         response = await fetch(client, url)