diff --git a/Gemfile b/Gemfile
index 79948bb..1f1d818 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ group :development do
 end
 
 group :test do
-  gem 'concurrent-ruby', '1.3.4'
+  gem 'concurrent-ruby', '1.3.6'
   gem 'rails', '~> 6'
   gem 'rspec-rails'
   gem 'rails-controller-testing'