diff --git a/moulinette/core.py b/moulinette/core.py
index 1bdd602a..894c85b8 100644
--- a/moulinette/core.py
+++ b/moulinette/core.py
@@ -412,8 +412,11 @@ def clean_session(session_id, profiles=[]):
 
 class MoulinetteError(StandardError):
     """Moulinette base exception"""
-    def __init__(self, key, *args, **kwargs):
-        msg = moulinette.m18n.g(key, *args, **kwargs)
+    def __init__(self, key, __raw_msg__=False, *args, **kwargs):
+        if __raw_msg__:
+            msg = key
+        else:
+            msg = moulinette.m18n.g(key, *args, **kwargs)
         super(MoulinetteError, self).__init__(msg)
         self.strerror = msg