~/D/g/h/heroku-buildpack-ruby (master) > g d
diff --git lib/language_pack/ruby.rb lib/language_pack/ruby.rb
index 88e42fa..2f9009b 100644
--- lib/language_pack/ruby.rb
+++ lib/language_pack/ruby.rb
@@ -634,7 +634,7 @@ BUNDLE
     instrument 'ruby.build_bundler' do
       log("bundle") do
         bundle_without = env("BUNDLE_WITHOUT") || default_bundle_without
-        bundle_bin     = "bundle"
+        bundle_bin     = "bundle _#{BUNDLER_VERSION}_"
         bundle_command = "#{bundle_bin} install --without #{bundle_without} --path vendor/bundle --binstubs #{bundler_binstubs_path}"
         bundle_command << " -j4"