diff --git a/rswag-api/open_api-rswag-api.gemspec b/rswag-api/open_api-rswag-api.gemspec
index 62f0d43..7c76a0c 100644
--- a/rswag-api/open_api-rswag-api.gemspec
+++ b/rswag-api/open_api-rswag-api.gemspec
@@ -13,5 +13,5 @@ Gem::Specification.new do |s|
 
   s.files = Dir["{lib}/**/*"] + ["MIT-LICENSE", "Rakefile"]
 
-  s.add_dependency 'railties', '>= 3.1'
+  s.add_dependency 'railties', '>= 3.1', '< 7.0'
 end