diff --git a/spectral_cube/cube_utils.py b/spectral_cube/cube_utils.py
index 3d39b1ecb..ab7150694 100644
--- a/spectral_cube/cube_utils.py
+++ b/spectral_cube/cube_utils.py
@@ -1002,9 +1002,9 @@ def update(self, n=1):
                 output_footprint=output_footprint,
                 reproject_function=reproject_interp,
                 progressbar=tqdm if verbose else False,
-                block_size=(None if spectral_block_size is None else
-                            [(spectral_block_size, cube.shape[1], cube.shape[2])
-                             for cube in cubes]),
+                block_sizes=(None if spectral_block_size is None else
+                             [(spectral_block_size, cube.shape[1], cube.shape[2])
+                              for cube in cubes]),
             )
         except TypeError as ex:
             # print the exception in case we caught a different TypeError than expected