diff --git a/mlair/data_handler/default_data_handler.py b/mlair/data_handler/default_data_handler.py
index 52835975101f5ce6881b72b127e16c0e299dfb14..ddf276cf2d88c108d8622c507471f989c4f99e8b 100644
--- a/mlair/data_handler/default_data_handler.py
+++ b/mlair/data_handler/default_data_handler.py
@@ -13,6 +13,7 @@ from functools import reduce
 from typing import Tuple, Union, List
 import multiprocessing
 import psutil
+import dask
 
 import numpy as np
 import xarray as xr
@@ -83,11 +84,20 @@ class DefaultDataHandler(AbstractDataHandler):
         if store_processed_data is True:
             self._cleanup() if fresh_store is True else None
             data = {"X": self._X, "Y": self._Y, "X_extreme": self._X_extreme, "Y_extreme": self._Y_extreme}
+            data = self._force_dask_computation(data)
             with open(self._save_file, "wb") as f:
                 pickle.dump(data, f)
             logging.debug(f"save pickle data to {self._save_file}")
             self._reset_data()
 
+    @staticmethod
+    def _force_dask_computation(data):
+        try:
+            data = dask.compute(data)[0]
+        except:
+            pass
+        return data
+
     def _load(self):
         try:
             with open(self._save_file, "rb") as f: