diff --git a/Tests/test_file_libtiff.py b/Tests/test_file_libtiff.py
index 21af32db644..7a94c0302f9 100644
--- a/Tests/test_file_libtiff.py
+++ b/Tests/test_file_libtiff.py
@@ -985,7 +985,7 @@ def test_open_missing_samplesperpixel(self):
             assert_image_equal_tofile(im, "Tests/images/old-style-jpeg-compression.png")
 
     @pytest.mark.parametrize(
-        "file_name,mode,size,tile",
+        "file_name, mode, size, tile",
         [
             (
                 "tiff_wrong_bits_per_sample.tiff",