diff --git a/Tests/test_file_avif.py b/Tests/test_file_avif.py
index 069a48940..036e9a8cb 100644
--- a/Tests/test_file_avif.py
+++ b/Tests/test_file_avif.py
@@ -256,7 +256,9 @@ class TestFileAvif:
             assert_image(im, "RGBA", (64, 64))
 
             # image has 876 transparent pixels
-            assert im.getchannel("A").getcolors()[0] == (876, 0)
+            colors = im.getchannel("A").getcolors()
+            assert colors is not None
+            assert colors[0] == (876, 0)
 
     def test_save_transparent(self, tmp_path: Path) -> None:
         im = Image.new("RGBA", (10, 10), (0, 0, 0, 0))