diff --git a/counter/migrations/0017_studentcard.py b/counter/migrations/0017_studentcard.py
index 963f77db..8304a104 100644
--- a/counter/migrations/0017_studentcard.py
+++ b/counter/migrations/0017_studentcard.py
@@ -1,7 +1,8 @@
 # -*- coding: utf-8 -*-
-# Generated by Django 1.11.13 on 2018-10-17 23:02
+# Generated by Django 1.11.13 on 2018-10-18 23:15
 from __future__ import unicode_literals
 
+import django.core.validators
 from django.db import migrations, models
 import django.db.models.deletion
 
@@ -25,7 +26,12 @@ class Migration(migrations.Migration):
                 ),
                 (
                     "uid",
-                    models.CharField(max_length=14, unique=True, verbose_name="uid"),
+                    models.CharField(
+                        max_length=14,
+                        unique=True,
+                        validators=[django.core.validators.MinLengthValidator(4)],
+                        verbose_name="uid",
+                    ),
                 ),
                 (
                     "customer",