diff --git a/db/models.py b/db/models.py
index a3f0d7a..dd45cd1 100644
--- a/db/models.py
+++ b/db/models.py
@@ -80,7 +80,7 @@ class OrdersPool(BaseModel):
         null=True
     )
 
-    updated_at = DateTimeField()
+    updated_at = DateTimeField(null=False)
 
     def to_dict(self):
         return {
diff --git a/migrations/021_not_null_orders_pool_updated_at.py b/migrations/021_not_null_orders_pool_updated_at.py
index 4d919d7..b909272 100644
--- a/migrations/021_not_null_orders_pool_updated_at.py
+++ b/migrations/021_not_null_orders_pool_updated_at.py
@@ -37,8 +37,14 @@ with suppress(ImportError):
 def migrate(migrator: Migrator, database: pw.Database, *, fake=False):
     """Write your migrations here."""
     
+    migrator.change_fields('orders_pool', updated_at=pw.DateTimeField())
+
+    migrator.add_not_null('orders_pool', 'updated_at')
 
 
 def rollback(migrator: Migrator, database: pw.Database, *, fake=False):
     """Write your rollback migrations here."""
     
+    migrator.change_fields('orders_pool', updated_at=pw.DateTimeField(null=True))
+
+    migrator.drop_not_null('orders_pool', 'updated_at')