caching.gemspec in caching-0.0.4 vs caching.gemspec in caching-0.0.5

@@ -16,9 +16,11 @@
   spec.files         = `git ls-files`.split($/)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
+  spec.add_runtime_dependency "concurrent-ruby"
+
   spec.add_development_dependency "bundler", "~> 1.3"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "minitest", "~> 4.7"
   spec.add_development_dependency "turn", "~> 0.9"
   spec.add_development_dependency "simplecov"