diff --git a/Tests/test_file_jpeg.py b/Tests/test_file_jpeg.py
index 91bf3cf74..a2481c336 100644
--- a/Tests/test_file_jpeg.py
+++ b/Tests/test_file_jpeg.py
@@ -934,7 +934,7 @@ class TestFileJpeg:
 
     def test_jpeg_magic_number(self, monkeypatch: pytest.MonkeyPatch) -> None:
         size = 4097
-        buffer = BytesIO(b"\xff" * size)  # Many xFF bytes
+        buffer = BytesIO(b"\xff" * size)  # Many xff bytes
         max_pos = 0
         orig_read = buffer.read