httpi.gemspec in httpi-4.0.2 vs httpi.gemspec in httpi-4.0.3

@@ -19,10 +19,10 @@
 
   s.required_ruby_version = '>= 3.0'
 
   s.license = 'MIT'
 
-  s.add_dependency 'rack', '>= 2.0', '< 3.1'
+  s.add_dependency 'rack', '>= 2.0', '< 4'
   s.add_dependency 'nkf'
   s.add_dependency 'base64'
   s.add_dependency 'mutex_m'
 
   s.add_development_dependency 'rubyntlm', '~> 0.6.4'