diff --git a/mailadmin/migrations/0004_auto_20150125_1401.py b/mailadmin/migrations/0004_auto_20150125_1401.py
index 7cd05be..75ccd10 100644
--- a/mailadmin/migrations/0004_auto_20150125_1401.py
+++ b/mailadmin/migrations/0004_auto_20150125_1401.py
@@ -9,7 +9,8 @@ def normalize_prefixes(apps, schema_editor):
     OrgUnit = apps.get_model("mailadmin", "OrgUnit")
 
     for ou in OrgUnit.objects.all():
-        Prefix.objects.create(name=ou.prefix, orgunit=ou)
+        if ou.prefix:
+            Prefix.objects.create(name=ou.prefix, orgunit=ou)
 
 
 def noop(*args, **kwargs):
diff --git a/mailadmin/models.py b/mailadmin/models.py
index 8881d92..1464ce1 100644
--- a/mailadmin/models.py
+++ b/mailadmin/models.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from django.contrib.auth.models import Group
 from django.db import models
 
@@ -27,9 +28,12 @@ class PrefixQueryset(models.QuerySet):
 
 class Prefix(models.Model):
     def __unicode__(self):
-        return self.name
+        return self.name or ''
 
     name = models.CharField(max_length=500, blank=True, null=True)
     orgunit = models.ForeignKey('mailadmin.OrgUnit', related_name='prefixes')
 
     objects = PrefixQueryset.as_manager()
+
+    class Meta:
+        verbose_name_plural = 'prefixes'
diff --git a/mailadmin/serializers.py b/mailadmin/serializers.py
index f28415d..e2fa961 100644
--- a/mailadmin/serializers.py
+++ b/mailadmin/serializers.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from django.conf import settings
 from django.contrib.auth.models import User, Group
 from rest_framework import serializers
diff --git a/mailadmin/views.py b/mailadmin/views.py
index d1566bb..5318626 100644
--- a/mailadmin/views.py
+++ b/mailadmin/views.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from django.conf import settings
 from django.contrib.auth import login, logout as auth_logout
 from django.contrib.auth.decorators import login_required