diff --git a/conftest.py b/conftest.py
index 1d776f8d..a319285e 100644
--- a/conftest.py
+++ b/conftest.py
@@ -30,9 +30,7 @@ def pytest_collection_modifyitems(items: list[pytest.Item]) -> None:
 
 
 @pytest.fixture(name="make_image_file")
-def fixture_make_image_file(
-    high_quality_image: io.BytesIO,
-) -> Generator[None]:
+def fixture_make_image_file(high_quality_image: io.BytesIO) -> Generator[None]:
     """Make an image file available in the test directory.
 
     The path of this file matches the path in the documentation.
@@ -45,9 +43,7 @@ def fixture_make_image_file(
 
 
 @pytest.fixture(name="mock_vws")
-def fixture_mock_vws(
-    monkeypatch: pytest.MonkeyPatch,
-) -> Generator[None]:
+def fixture_mock_vws(monkeypatch: pytest.MonkeyPatch) -> Generator[None]:
     """Yield a mock VWS.
 
     The keys used here match the keys in the documentation.
diff --git a/tests/conftest.py b/tests/conftest.py
index 3831755a..99ed568f 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -5,7 +5,7 @@
 import io
 from collections.abc import Generator
 from pathlib import Path
-from typing import IO, BinaryIO, Literal
+from typing import IO, Literal
 
 import pytest
 from mock_vws import MockVWS
@@ -53,7 +53,7 @@ def fixture_image_file(
     high_quality_image: io.BytesIO,
     tmp_path: Path,
     request: pytest.FixtureRequest,
-) -> Generator[BinaryIO]:
+) -> Generator[IO[bytes]]:
     """
     An image file object.
     """
@@ -69,7 +69,7 @@ def fixture_image_file(
 def image(
     request: pytest.FixtureRequest,
     high_quality_image: io.BytesIO,
-    image_file: BinaryIO,
+    image_file: IO[bytes],
 ) -> IO[bytes]:
     """
     An image in any of the types that the API accepts.