diff --git a/tilecloud_chain/__init__.py b/tilecloud_chain/__init__.py
index baac4cdd3..fcfb0bc23 100644
--- a/tilecloud_chain/__init__.py
+++ b/tilecloud_chain/__init__.py
@@ -1560,7 +1560,7 @@ def __call__(self, tile: Tile) -> Tile:
             assert tile.data
             _LOGGER.exception("%s: %s", str(ex), tile.data)
             raise
-        for px in image.getdata():
+        for px in image.getdata():  # type: ignore[attr-defined]
             if ref is None:
                 ref = px
             elif px != ref: