diff --git a/Gemfile b/Gemfile
index 113de35..b7fc136 100644
--- a/Gemfile
+++ b/Gemfile
@@ -22,6 +22,7 @@ gemspec
 
 group :development, :test do
   gem 'faraday-httpclient'
+  gem 'mutex_m' if RUBY_VERSION >= '3.4'
   gem 'faraday-net_http_persistent'
   gem 'faraday-typhoeus'
   gem 'faraday-excon'
diff --git a/spec/elastic/transport/client_spec.rb b/spec/elastic/transport/client_spec.rb
index a2a8143..967a1f0 100644
--- a/spec/elastic/transport/client_spec.rb
+++ b/spec/elastic/transport/client_spec.rb
@@ -1469,6 +1469,7 @@
 
           context 'when using the HTTPClient adapter' do
             require 'faraday/httpclient'
+            require 'mutex_m' if RUBY_VERSION >= '3.4'
 
             let(:client) do
               described_class.new(hosts: ELASTICSEARCH_HOSTS, compression: true, adapter: :httpclient, enable_meta_header: false)