diff --git a/ruby/Gemfile b/ruby/Gemfile
index e6b5db96cee2889edb679136e2903fcbc0a7a57d..d0a7208c1e559dec163f3beef580c8344e34f33f 100644
--- a/ruby/Gemfile
+++ b/ruby/Gemfile
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 source "https://rubygems.org"
 
-#gem 'mmap', git: 'https://github.com/lyda/mmap.git', :branch => 'non-global-version'
-gem 'mmap', git: 'https://github.com/epitron/mmap.git'
+gem 'mmap', git: 'https://github.com/lyda/mmap.git', :branch => 'modern-ruby'
+#gem 'mmap', git: 'https://github.com/epitron/mmap.git'