diff --git a/ros-apartment.gemspec b/ros-apartment.gemspec
index 41ede576..cdaa0b37 100644
--- a/ros-apartment.gemspec
+++ b/ros-apartment.gemspec
@@ -30,7 +30,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'activerecord', '>= 6.1.0', '< 7.2'
   s.add_dependency 'parallel', '< 2.0'
   s.add_dependency 'public_suffix', '>= 2.0.5', '< 6.0'
-  s.add_dependency 'rack', '>= 1.3.6', '< 3.0'
+  s.add_dependency 'rack', '>= 1.3.6', '< 4.0'
 
   s.add_development_dependency 'appraisal', '~> 2.2'
   s.add_development_dependency 'bundler', '>= 1.3', '< 3.0'