diff --git a/hermes_eea/calibration/calibration.py b/hermes_eea/calibration/calibration.py
index eb7207a..55fa193 100644
--- a/hermes_eea/calibration/calibration.py
+++ b/hermes_eea/calibration/calibration.py
@@ -248,7 +248,7 @@ def l0_sci_data_to_cdf(stepper, data: dict, original_filename: Path, destination
         try:
             # this writes out the data to CDF file format
             cdf_path = hermes_eea_factory.hermes_eea_data.save(
-                str(destination_dir), True
+                destination_dir, True
             )
         except Exception as e:
             log.error(e)
diff --git a/hermes_eea/tests/test_calibration.py b/hermes_eea/tests/test_calibration.py
index 917c82b..71b4b18 100644
--- a/hermes_eea/tests/test_calibration.py
+++ b/hermes_eea/tests/test_calibration.py
@@ -71,7 +71,7 @@ def verify_l1a(stepper, output_l1a):
     """
     from hermes_eea.io.EEA import REAL4FILL, EPOCHTIMEFILL, INTFILL
     assert os.path.getsize(output_l1a) > 275000
-    with pycdf.CDF(output_l1a) as cdf:
+    with pycdf.CDF(str(output_l1a)) as cdf:
 
         # overall structure
         length_vars = len(cdf["Epoch"][:])