diff --git a/gemfiles/rails_61.gemfile b/gemfiles/rails_61.gemfile
index 12cdc2b7..69ff74e0 100644
--- a/gemfiles/rails_61.gemfile
+++ b/gemfiles/rails_61.gemfile
@@ -16,5 +16,6 @@ gem "rails", ">= 6.1", "< 7.0"
 gem "mysql2", "0.5.5"
 gem "pg"
 gem "sqlite3", "~> 1.4"
+gem "concurrent-ruby", "1.3.4"
 
 gemspec path: "../"
diff --git a/gemfiles/rails_70.gemfile b/gemfiles/rails_70.gemfile
index 598010ba..b9a1ca0c 100644
--- a/gemfiles/rails_70.gemfile
+++ b/gemfiles/rails_70.gemfile
@@ -13,5 +13,6 @@ gem "rails", "7.0.3"
 gem "mysql2", "0.5.5"
 gem "pg"
 gem "sqlite3", "~> 1.4"
+gem "concurrent-ruby", "1.3.4"
 
 gemspec path: "../"