diff --git a/mrml-rails.gemspec b/mrml-rails.gemspec
index ed857d1..43f375d 100644
--- a/mrml-rails.gemspec
+++ b/mrml-rails.gemspec
@@ -24,5 +24,5 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'mrml', '~> 1.0'
   spec.add_runtime_dependency 'railties', '>= 3.1'
   spec.add_development_dependency 'rspec', '~> 3.10'
-  spec.add_development_dependency 'rspec-rails', '>= 4.0.2', '~> 5.0'
+  spec.add_development_dependency 'rspec-rails', '>= 4.0.2', '~> 6.0'
 end