diff --git a/openai/tests/test_file_cli.py b/openai/tests/test_file_cli.py
index 69ea29e2a0..7fb2bf10b0 100644
--- a/openai/tests/test_file_cli.py
+++ b/openai/tests/test_file_cli.py
@@ -1,30 +1,32 @@
 import json
 import subprocess
 import time
-from tempfile import NamedTemporaryFile
+from pathlib import Path
 
 STILL_PROCESSING = "File is still processing. Check back later."
 
 
-def test_file_cli() -> None:
+def test_file_cli(tmp_path: Path) -> None:
     contents = json.dumps({"prompt": "1 + 3 =", "completion": "4"}) + "\n"
-    with NamedTemporaryFile(suffix=".jsonl", mode="wb") as train_file:
-        train_file.write(contents.encode("utf-8"))
-        train_file.flush()
-        create_output = subprocess.check_output(
-            ["openai", "api", "files.create", "-f", train_file.name, "-p", "fine-tune"]
-        )
+    train_file = tmp_path / "data.jsonl"
+    train_file.write_bytes(contents.encode("utf-8"))
+    create_output = subprocess.check_output(
+        ["openai", "api", "files.create", "-f", str(train_file), "-p", "fine-tune"]
+    )
+
     file_obj = json.loads(create_output)
     assert file_obj["bytes"] == len(contents)
+
     file_id: str = file_obj["id"]
     assert file_id.startswith("file-")
+
     start_time = time.time()
     while True:
         delete_result = subprocess.run(
             ["openai", "api", "files.delete", "-i", file_id],
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
-            encoding="utf-8",
+            text=True,
         )
         if delete_result.returncode == 0:
             break
diff --git a/openai/tests/test_long_examples_validator.py b/openai/tests/test_long_examples_validator.py
index 949a7cbbae..610cea88f8 100644
--- a/openai/tests/test_long_examples_validator.py
+++ b/openai/tests/test_long_examples_validator.py
@@ -1,6 +1,6 @@
 import json
 import subprocess
-from tempfile import NamedTemporaryFile
+from pathlib import Path
 
 import pytest
 
@@ -10,7 +10,7 @@
 
 @pytest.mark.skipif(not HAS_PANDAS, reason=PANDAS_INSTRUCTIONS)
 @pytest.mark.skipif(not HAS_NUMPY, reason=NUMPY_INSTRUCTIONS)
-def test_long_examples_validator() -> None:
+def test_long_examples_validator(tmp_path: Path) -> None:
     """
     Ensures that long_examples_validator() handles previously applied recommendations,
     namely dropped duplicates, without resulting in a KeyError.
@@ -30,21 +30,19 @@ def test_long_examples_validator() -> None:
         {"prompt": long_prompt, "completion": long_completion},  # 2 of 2 duplicates
     ]
 
-    with NamedTemporaryFile(suffix=".jsonl", mode="w") as training_data:
-        print(training_data.name)
+    train_file = tmp_path / "data.jsonl"
+    print(train_file)  # show the full path to the temporary file
+    with open(train_file, mode="w", encoding="utf-8") as file:
         for prompt_completion_row in unprepared_training_data:
-            training_data.write(json.dumps(prompt_completion_row) + "\n")
-            training_data.flush()
-
-        prepared_data_cmd_output = subprocess.run(
-            [f"openai tools fine_tunes.prepare_data -f {training_data.name}"],
-            stdout=subprocess.PIPE,
-            text=True,
-            input="y\ny\ny\ny\ny",  # apply all recommendations, one at a time
-            stderr=subprocess.PIPE,
-            encoding="utf-8",
-            shell=True,
-        )
+            print(json.dumps(prompt_completion_row), file=file)
+
+    prepared_data_cmd_output = subprocess.run(
+        ["openai", "tools", "fine_tunes.prepare_data", "-f", str(train_file)],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        input="y\ny\ny\ny\ny",  # apply all recommendations, one at a time
+        text=True,
+    )
 
     # validate data was prepared successfully
     assert prepared_data_cmd_output.stderr == ""
diff --git a/openai/tests/test_util.py b/openai/tests/test_util.py
index 6220ccb7f4..4b3d812e14 100644
--- a/openai/tests/test_util.py
+++ b/openai/tests/test_util.py
@@ -1,32 +1,26 @@
 import json
-from tempfile import NamedTemporaryFile
+from pathlib import Path
 
 import pytest
+from pytest import MonkeyPatch
 
-import openai
 from openai import util
 
 
 @pytest.fixture(scope="function")
-def api_key_file():
-    saved_path = openai.api_key_path
-    try:
-        with NamedTemporaryFile(prefix="openai-api-key", mode="wt") as tmp:
-            openai.api_key_path = tmp.name
-            yield tmp
-    finally:
-        openai.api_key_path = saved_path
-
-
-def test_openai_api_key_path(api_key_file) -> None:
-    print("sk-foo", file=api_key_file)
-    api_key_file.flush()
+def api_key_file(tmp_path: Path, monkeypatch: MonkeyPatch) -> Path:
+    key_file = tmp_path / "openai_api_key"
+    monkeypatch.setattr("openai.api_key_path", str(key_file))
+    return key_file
+
+
+def test_openai_api_key_path(api_key_file: Path) -> None:
+    api_key_file.write_text("sk-foo\n", encoding="utf-8")
     assert util.default_api_key() == "sk-foo"
 
 
-def test_openai_api_key_path_with_malformed_key(api_key_file) -> None:
-    print("malformed-api-key", file=api_key_file)
-    api_key_file.flush()
+def test_openai_api_key_path_with_malformed_key(api_key_file: Path) -> None:
+    api_key_file.write_text("malformed-api-key\n", encoding="utf-8")
     with pytest.raises(ValueError, match="Malformed API key"):
         util.default_api_key()