diff --git a/tryton/common/common.py b/tryton/common/common.py
index a5dc066ba7..53accdffac 100644
--- a/tryton/common/common.py
+++ b/tryton/common/common.py
@@ -1151,6 +1151,7 @@ def generateColorscheme(masterColor, keys, light=0.1):
 class RPCException(Exception):
 
     def __init__(self, exception):
+        super(RPCException, self).__init__(exception)
         self.exception = exception