diff --git a/src/disp_s1/product.py b/src/disp_s1/product.py
index 17402b8..a8dd1e9 100644
--- a/src/disp_s1/product.py
+++ b/src/disp_s1/product.py
@@ -352,7 +352,8 @@ def _get_start_end_cslcs(files):
 
         for info, filename in zip(product_infos[3:], data_files, strict=True):
             if filename is not None and Path(filename).exists():
-                data = io.load_gdal(filename).astype(info.dtype)
+                data = io.load_gdal(filename, masked=True).filled(info.fillvalue)
+                data = data.astype(info.dtype)
             else:
                 data = np.full(shape=shape, fill_value=info.fillvalue, dtype=info.dtype)