diff --git a/organize/interfaces.py b/organize/interfaces.py
index e550049..b39e841 100644
--- a/organize/interfaces.py
+++ b/organize/interfaces.py
@@ -1,5 +1,5 @@
 #
-#  Copyright (c) 2013 Helmut Merz helmutm@cy55.de
+#  Copyright (c) 2015 Helmut Merz helmutm@cy55.de
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -67,10 +67,13 @@ class UserId(schema.TextLine):
                                    mapping={'userId': userId}))
         person = getPersonForUser(context, principal=principal)
         if person is not None and person != context:
-            raiseValidationError(
-                _(u'There is alread a person ($person) assigned to user $userId.',
-                  mapping=dict(person=zapi.getName(person),
-                               userId=userId)))
+            name = zapi.getName(person)
+            if name:
+                raiseValidationError(
+                    _(u'There is already a person ($person) '
+                      u'assigned to user $userId.',
+                      mapping=dict(person=name,
+                                   userId=userId)))
 
 
 class LoginName(schema.TextLine):
@@ -82,7 +85,7 @@ class LoginName(schema.TextLine):
         super(LoginName, self)._validate(userId)
         if userId in getPrincipalFolder(self.context):
             raiseValidationError(
-                _(u'There is alread a user with ID $userId.',
+                _(u'There is already a user with ID $userId.',
                   mapping=dict(userId=userId)))
 
 
diff --git a/organize/party.py b/organize/party.py
index c83ac40..7cfd52c 100644
--- a/organize/party.py
+++ b/organize/party.py
@@ -1,5 +1,5 @@
 #
-#  Copyright (c) 2014 Helmut Merz helmutm@cy55.de
+#  Copyright (c) 2015 Helmut Merz helmutm@cy55.de
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -93,9 +93,11 @@ class Person(AdapterBase, BasePerson):
                 return
             person = getPersonForUser(self.context, principal=principal)
             if person is not None and person != self.context:
-                raise ValueError(
-                    'There is alread a person (%s) assigned to user %s.'
-                    % (getName(person), userId))
+                name = getName(person)
+                if name:
+                    raise ValueError(
+                        'There is already a person (%s) assigned to user %s.'
+                        % (getName(person), userId))
             pa = annotations(principal)
             loopsId = util.getUidForObject(self.context.getLoopsRoot())
             ann = pa.get(ANNOTATION_KEY)