diff --git a/pyproject.toml b/pyproject.toml
index 0488b3b9d1..fc429193a3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -290,7 +290,6 @@ module = [
     "tests.test_util.test_util",
     "tests.test_util.test_util_display",
     "tests.test_util.test_util_docutils",
-    "tests.test_util.test_util_images",
     "tests.test_util.test_util_inventory",
     # tests/test_writers
     "tests.test_writers.test_docutilsconf",
diff --git a/tests/test_util/test_util_images.py b/tests/test_util/test_util_images.py
index b56d68c108..875fc0d98f 100644
--- a/tests/test_util/test_util_images.py
+++ b/tests/test_util/test_util_images.py
@@ -11,13 +11,17 @@ from sphinx.util.images import (
     parse_data_uri,
 )
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from pathlib import Path
+
 GIF_FILENAME = 'img.gif'
 PNG_FILENAME = 'img.png'
 PDF_FILENAME = 'img.pdf'
 TXT_FILENAME = 'index.txt'
 
 
-def test_get_image_size(rootdir):
+def test_get_image_size(rootdir: Path) -> None:
     assert get_image_size(rootdir / 'test-root' / GIF_FILENAME) == (200, 181)
     assert get_image_size(rootdir / 'test-root' / PNG_FILENAME) == (200, 181)
     assert get_image_size(rootdir / 'test-root' / PDF_FILENAME) is None