diff --git a/db/migrate/20190810150332_create_groups.rb b/db/migrate/20190810150332_create_groups.rb
index a7d6161..43089fb 100644
--- a/db/migrate/20190810150332_create_groups.rb
+++ b/db/migrate/20190810150332_create_groups.rb
@@ -1,10 +1,10 @@
 class CreateGroups < ActiveRecord::Migration[5.2]
   def change
     create_table :groups do |t|
-      t.integer :chat_id, :limit => 18
+      t.bigint :chat_id
       t.string :username
 
       t.timestamps
     end
   end
 end