diff --git a/weboob/backend.py b/weboob/backend.py
index 5d956dc2..54a77e66 100644
--- a/weboob/backend.py
+++ b/weboob/backend.py
@@ -16,7 +16,6 @@
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 
-from copy import deepcopy
 import re
 import os
 from threading import RLock
@@ -117,7 +116,7 @@ class BaseBackend(object):
                     value = float(value)
             self.config[name] = value
         self.storage = BackendStorage(self.name, storage)
-        self.storage.load(deepcopy(self.STORAGE))
+        self.storage.load(self.STORAGE)
 
     @property
     def browser(self):
diff --git a/weboob/tools/storage.py b/weboob/tools/storage.py
index 77ae6db4..a89169d6 100644
--- a/weboob/tools/storage.py
+++ b/weboob/tools/storage.py
@@ -15,6 +15,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
+from copy import deepcopy
 from logging import error
 
 class IStorage:
@@ -42,7 +43,7 @@ else:
 
         def load(self, backend, default={}):
             d = self.config.values.get(backend, {})
-            self.config.values[backend] = default.copy()
+            self.config.values[backend] = deepcopy(default)
             self.config.values[backend].update(d)
 
         def save(self, backend):