diff --git a/Tests/images/bc4_unorm.png b/Tests/images/bc4_unorm.png
new file mode 100644
index 000000000..71d536c84
Binary files /dev/null and b/Tests/images/bc4_unorm.png differ
diff --git a/Tests/test_file_dds.py b/Tests/test_file_dds.py
index 85a3ae172..337f541f6 100644
--- a/Tests/test_file_dds.py
+++ b/Tests/test_file_dds.py
@@ -93,6 +93,8 @@ def test_dx10_bc4():
         assert im.mode == "L"
         assert im.size == (64, 64)
 
+        assert_image_equal_tofile(im, TEST_FILE_DX10_BC4_UNORM.replace(".dds", ".png"))
+
 
 @pytest.mark.parametrize(
     "image_path",