diff --git a/tryton/tryton/common/common.py b/tryton/tryton/common/common.py
index b36ea9ab98..17e0082e48 100644
--- a/tryton/tryton/common/common.py
+++ b/tryton/tryton/common/common.py
@@ -1323,7 +1323,9 @@ class RPCProgress(object):
 
         def return_():
             if self.exception:
-                raise RPCException(self.exception)
+                if not isinstance(self.exception, RPCException):
+                    raise RPCException(self.exception)
+                raise self.exception
             else:
                 return self.res