diff --git a/nifty4/multi/multi_domain.py b/nifty4/multi/multi_domain.py
index 90894bedc4f7bab1a430b20cacd9c240bc0fae28..fc2116f7d5de2cdeecf066f9ce2a42121a57cb32 100644
--- a/nifty4/multi/multi_domain.py
+++ b/nifty4/multi/multi_domain.py
@@ -49,7 +49,7 @@ class MultiDomain(frozendict):
 
     def __init__(self, domain, _callingfrommake=False):
         if not _callingfrommake:
-            raise NotImplementedError
+            raise NotImplementedError('To create a MultiDomain call `MultiDomain.make()`.')
         super(MultiDomain, self).__init__(domain)
 
     @staticmethod