diff --git a/sidekiq.gemspec b/sidekiq.gemspec
index bd033e183..f85d5f535 100644
--- a/sidekiq.gemspec
+++ b/sidekiq.gemspec
@@ -19,7 +19,7 @@ Gem::Specification.new do |gem|
   gem.add_dependency                  'redis-namespace', '~> 1.5', '>= 1.5.2'
   gem.add_dependency                  'connection_pool', '~> 2.2', '>= 2.2.0'
   gem.add_dependency                  'json', '~> 1.0'
-  gem.add_dependency                  'concurrent-ruby', '1.0.0.pre4'
+  gem.add_dependency                  'concurrent-ruby', '~> 1.0.0.pre5'
   gem.add_development_dependency      'sinatra', '~> 1.4', '>= 1.4.6'
   gem.add_development_dependency      'minitest', '~> 5.7', '>= 5.7.0'
   gem.add_development_dependency      'rake', '~> 10.0'