diff --git a/Tests/test_file_jpeg.py b/Tests/test_file_jpeg.py
index f8513235683..c02e53b8cc5 100644
--- a/Tests/test_file_jpeg.py
+++ b/Tests/test_file_jpeg.py
@@ -664,7 +664,7 @@ def test_restart_markers(self):
                 subsampling=0,
             )
             found_markers = sum(
-                len(out.getvalue().split(bytes([0xff, 0xd0 + i]))) - 1 for i in range(8)
+                len(out.getvalue().split(bytes([0xFF, 0xD0 + i]))) - 1 for i in range(8)
             )
             assert markers == found_markers