diff --git a/sinatra.gemspec b/sinatra.gemspec
index e742856a..e9160005 100644
--- a/sinatra.gemspec
+++ b/sinatra.gemspec
@@ -42,7 +42,7 @@ EOF
 
   s.required_ruby_version = '>= 2.6.0'
 
-  s.add_dependency 'rack', '~> 2.2'
+  s.add_dependency 'rack', '~> 2.2', '>= 2.2.4'
   s.add_dependency 'tilt', '~> 2.0'
   s.add_dependency 'rack-protection', version
   s.add_dependency 'mustermann', '~> 1.0'