diff --git a/resolve/data/observation.py b/resolve/data/observation.py
index c51f7706f72d2101a899d598061df6ad29b914c7..e6e9c42e91233ce6a9c71072759730f60b9072f9 100644
--- a/resolve/data/observation.py
+++ b/resolve/data/observation.py
@@ -362,7 +362,7 @@ class Observation(BaseObservation):
         for rank in range(ntask):
             lo, hi = ift.utilities.shareRange(nwork, ntask, rank)
             obs = Observation.load(data_path, (lo, hi))
-            obs.save(f"{target_folder}/{base_name}_{rank}.npz")
+            obs.save(f"{target_folder}/{base_name}_{rank}.npz", compress=False)
 
 
     @staticmethod