diff --git a/Gemfile b/Gemfile
index 3c8be96..d252594 100644
--- a/Gemfile
+++ b/Gemfile
@@ -29,7 +29,6 @@ gem 'sidekiq-congestion', '~> 0.1.0'
 gem 'sidekiq-cron'
 gem 'spring', group: :development
 gem 'zoo_stream', '~> 1.0'
-gem 'concurrent-ruby', '1.3.4'
 
 group :test, :development do
   gem 'benchmark-ips'
diff --git a/Gemfile.lock b/Gemfile.lock
index 524d328..10739ba 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -368,7 +368,6 @@ DEPENDENCIES
   aws-sdk (~> 2.3.7)
   benchmark-ips
   codeclimate-test-reporter (~> 0.5)
-  concurrent-ruby (= 1.3.4)
   factory_bot_rails (~> 4.11.1)
   faraday
   faraday_middleware