hot_module.gemspec in hot_module-1.0.0.alpha10 vs hot_module.gemspec in hot_module-1.0.0.alpha11

@@ -25,9 +25,10 @@
       (f == __FILE__) || f.match(%r{\A(?:(?:bin|test|spec|features)/|\.(?:git|travis|circleci)|appveyor)})
     end
   end
   spec.require_paths = ["lib"]
 
+  spec.add_dependency "concurrent-ruby", "~> 1.2"
   spec.add_dependency "nokolexbor", ">= 0.4.2"
 
   spec.add_development_dependency "hash_with_dot_access", "~> 1.2"
 end