diff --git a/programmer/models.py b/programmer/models.py
index 303c1bf..d12959e 100644
--- a/programmer/models.py
+++ b/programmer/models.py
@@ -71,11 +71,10 @@ class Solution(models.Model):
     is_published = models.BooleanField(default=True, verbose_name='Опубликован')
     slug = models.SlugField(
         max_length=255,
-        unique=False,          # временно не уникальное
+        unique=True,
         db_index=True,
         verbose_name='URL-идентификатор',
         blank=True,
-        null=True,             # разрешаем NULL
     )
     def __str__(self):
         return self.title