diff --git a/README.md b/README.md
index 9733ea7..a81b504 100644
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ Please make sure it doesn't break your existing code before upgrading to 1.0.
 Add following line to your Gemfile:
 
 ```ruby
-gem 'telegram-bot-ruby', '~> 1.0'
+gem 'telegram-bot-ruby', '~> 2.1'
 ```
 
 And then execute: