diff --git a/beat/backend/python/data_loaders.py b/beat/backend/python/data_loaders.py
index 7c034dd875cfe42af1bb4c8092928d47ad650ba4..429a26d4f29254b61d697f8f3aad8db8a0f37344 100644
--- a/beat/backend/python/data_loaders.py
+++ b/beat/backend/python/data_loaders.py
@@ -310,6 +310,17 @@ class DataLoader(object):
 
         return (result, indices[0], indices[1])
 
+    def __getstate__(self):
+        state = self.__dict__.copy()
+
+        #  reset the data cached as its content is not pickable
+        for infos in state["infos"].values():
+            infos["data"] = None
+            infos["start_index"] = -1
+            infos["end_index"] = -1
+
+        return state
+
 
 # ----------------------------------------------------------