diff --git a/lib/rubygems/vendored_net_http.rb b/lib/rubygems/vendored_net_http.rb
index 0c0f8d446d6394..a84c52a9470675 100644
--- a/lib/rubygems/vendored_net_http.rb
+++ b/lib/rubygems/vendored_net_http.rb
@@ -1,3 +1,5 @@
 # frozen_string_literal: true
 
-require_relative "vendor/net-http/lib/net/http"
+# Ruby 3.3 and RubyGems 3.5 is already load Gem::Timeout from lib/rubygems/net/http.rb
+# We should avoid to load it again
+require_relative "vendor/net-http/lib/net/http" unless defined?(Gem::Net::HTTP)
diff --git a/lib/rubygems/vendored_timeout.rb b/lib/rubygems/vendored_timeout.rb
index 6b8e1c7aa86eac..45541928e672d4 100644
--- a/lib/rubygems/vendored_timeout.rb
+++ b/lib/rubygems/vendored_timeout.rb
@@ -1,3 +1,5 @@
 # frozen_string_literal: true
 
-require_relative "vendor/timeout/lib/timeout"
+# Ruby 3.3 and RubyGems 3.5 is already load Gem::Timeout from lib/rubygems/timeout.rb
+# We should avoid to load it again
+require_relative "vendor/timeout/lib/timeout" unless defined?(Gem::Timeout)