diff -r b5daed0ce08b -r 4f07ad576fee src/app_migrations/registration/0001_initial.py
--- a/src/app_migrations/registration/0001_initial.py	Tue May 05 15:21:52 2015 +0200
+++ b/src/app_migrations/registration/0001_initial.py	Tue May 12 14:57:27 2015 +0200
@@ -17,7 +17,7 @@
             fields=[
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
                 ('activation_key', models.CharField(max_length=40, verbose_name='activation key')),
-                ('user', models.ForeignKey(verbose_name='user', to=settings.AUTH_USER_MODEL, unique=True)),
+                ('user', models.OneToOneField(verbose_name='user', to=settings.AUTH_USER_MODEL)),
             ],
             options={
                 'verbose_name': 'registration profile',