diff --git a/weboob/tools/application/base.py b/weboob/tools/application/base.py
index 0ae4d1b3..dded9e8e 100644
--- a/weboob/tools/application/base.py
+++ b/weboob/tools/application/base.py
@@ -247,6 +247,9 @@ class BaseApplication(object):
         return version
 
     def _do_complete_obj(self, backend, fields, obj):
+        if not obj:
+            return obj
+
         obj.backend = backend.name
         if fields is None or len(fields) > 0:
             backend.fillobj(obj, fields)