diff --git a/lib/vagrant/util/downloader.rb b/lib/vagrant/util/downloader.rb
index 8756fc3..7fb2be8 100644
--- a/lib/vagrant/util/downloader.rb
+++ b/lib/vagrant/util/downloader.rb
@@ -215,8 +215,9 @@ module Vagrant
         # If we're in Vagrant, then we use the packaged CA bundle
         if Vagrant.in_installer?
           subprocess_options[:env] ||= {}
-          subprocess_options[:env]["CURL_CA_BUNDLE"] =
-            File.expand_path("cacert.pem", ENV["VAGRANT_INSTALLER_EMBEDDED_DIR"])
+          # Use system certificates.
+          # subprocess_options[:env]["CURL_CA_BUNDLE"] =
+          #   File.expand_path("cacert.pem", ENV["VAGRANT_INSTALLER_EMBEDDED_DIR"])
         end
 
         return [options, subprocess_options]