diff --git a/app/models/group.rb b/app/models/group.rb
index 0dbb19f..a17f5c3 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -1,4 +1,5 @@
 class Group < ApplicationRecord
   has_many :asds
   has_many :special_events
+  validates :chat_id, uniqueness: true
 end
diff --git a/app/models/sender.rb b/app/models/sender.rb
index 138310d..ad86ebd 100644
--- a/app/models/sender.rb
+++ b/app/models/sender.rb
@@ -1,3 +1,4 @@
 class Sender < ApplicationRecord
   has_many :asds
+  validates :chat_id, uniqueness: true
 end