diff --git a/Gemfile b/Gemfile
index a12fd76..a2fa391 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 gem 'vonage'
 gem 'dotenv'
 gem 'faye-websocket', '0.11.0'
-gem 'sinatra', '2.1.0'
+gem 'sinatra', '4.2.0'
 gem 'sinatra-contrib', '2.1.0'
 gem 'rack-contrib', '2.3.0'
 gem 'thin', '1.8.0'