diff --git a/frontend/models.py b/frontend/models.py
index 05cc5f9..2c55e67 100644
--- a/frontend/models.py
+++ b/frontend/models.py
@@ -27,9 +27,9 @@ class PersonGlobalIdentity(models.Model):
 
 
 class  CitaviProjectIdentity(models.Model):
-    global_identity = models.ForeignKey(PersonGlobalIdentity)
-    project_id = models.ForeignKey(Project)
-    citavi_uuid = models.CharField(max_length=255)
+    global_identity = models.ForeignKey(PersonGlobalIdentity, blank=True, null=True)
+    project_id = models.ForeignKey(Project, blank=False, null=False)
+    citavi_uuid = models.CharField(max_length=255, blank=False, null=False)
     preferred_id = models.BooleanField()
     
     def __unicode__(self):