diff --git a/src/vampires_dpp/cli/centroids.py b/src/vampires_dpp/cli/centroids.py
index 0e33806..bf34ec2 100644
--- a/src/vampires_dpp/cli/centroids.py
+++ b/src/vampires_dpp/cli/centroids.py
@@ -125,7 +125,7 @@ def centroid(config: Path, filenames, num_proc, outdir, manual, plot):
     else:
         name = paths.aux / f"{pipeline_config.name}_raw_psf"
         # choose 4 to 20 files, depending on file size (avoid loading more than 500 frames, ~2GB of MBI)
-        number_files = max(4, min(10, 500 // table["NAXIS3"].median()))
+        number_files = int(max(4, min(10, 500 // table["NAXIS3"].median())))
         input_hduls_dict = create_raw_input_psfs(table, basename=name, max_files=number_files)
         centroids = {}
         for key, input_hdul in input_hduls_dict.items():
diff --git a/src/vampires_dpp/pdi/processing.py b/src/vampires_dpp/pdi/processing.py
index f06e4e5..d853f87 100644
--- a/src/vampires_dpp/pdi/processing.py
+++ b/src/vampires_dpp/pdi/processing.py
@@ -77,7 +77,7 @@ def polarization_calibration_triplediff(filenames: Sequence[str]):
         header_dict[key] = prim_hdr
         cube_dict[key] = cube_derot
         cube_errs[key] = cube_err_derot
-
+    assert len(cube_dict) == 16
     # reproject cam 2 onto cam 1
     for subkey in itertools.product((0.0, 45.0, 22.5, 67.5), ("A", "B")):
         key1 = (subkey[0], subkey[1], 1)