diff --git a/sass-rails.gemspec b/sass-rails.gemspec
index e40ee61..04c294a 100644
--- a/sass-rails.gemspec
+++ b/sass-rails.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |s|
   s.description = %q{Sass adapter for the Rails asset pipeline.}
   s.license     = %q{MIT}
 
-  s.add_dependency 'railties',        '>= 4.0.0', '< 5.1'
+  s.add_dependency 'railties',        '>= 4.0.0', '< 6'
   s.add_dependency 'sass',            '~> 3.4'
   s.add_dependency 'sprockets-rails', '< 4.0'
   s.add_dependency 'sprockets',       '~> 4.x'