diff --git a/onfido.gemspec b/onfido.gemspec
index 2e47902..73ea004 100644
--- a/onfido.gemspec
+++ b/onfido.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rspec', '~> 3.1'
   spec.add_development_dependency 'rspec-its', '~> 1.2'
   spec.add_development_dependency 'rubocop', '~> 0.51.0'
-  spec.add_development_dependency 'sinatra', '~> 1.4'
+  spec.add_development_dependency 'sinatra', '~> 2.0'
   spec.add_development_dependency 'webmock', '~> 3.0'
 
   spec.add_dependency 'rack', '>= 1.6.0'