diff --git a/src/objecttypes/token/models.py b/src/objecttypes/token/models.py
index c6d900eb..6b2bcea0 100644
--- a/src/objecttypes/token/models.py
+++ b/src/objecttypes/token/models.py
@@ -6,7 +6,7 @@
 
 
 class TokenAuth(models.Model):
-    token = models.CharField(_("token"), max_length=40, db_index=True)
+    token = models.CharField(_("token"), max_length=40, unique=True)
     contact_person = models.CharField(
         _("contact person"),
         max_length=200,