diff --git a/django_etesync/models.py b/django_etesync/models.py
index edfb18d..98f57f2 100644
--- a/django_etesync/models.py
+++ b/django_etesync/models.py
@@ -21,7 +21,7 @@ from django.utils.functional import cached_property
 
 
 Base64Url256BitValidator = RegexValidator(regex=r'^[a-zA-Z0-9\-_]{43}$', message='Expected a 256bit base64url.')
-UidValidator = RegexValidator(regex=r'[a-zA-Z0-9]', message='Not a valid UID')
+UidValidator = RegexValidator(regex=r'^[a-zA-Z0-9]*$', message='Not a valid UID')
 
 
 class Collection(models.Model):