diff --git a/lib/vagrant/action/builtin/cloud_init_setup.rb b/lib/vagrant/action/builtin/cloud_init_setup.rb
index a53b8fc3b..2e9be9b5d 100644
--- a/lib/vagrant/action/builtin/cloud_init_setup.rb
+++ b/lib/vagrant/action/builtin/cloud_init_setup.rb
@@ -20,7 +20,7 @@ module Vagrant
 
           if !user_data_configs.empty?
             user_data = setup_user_data(machine, env, user_data_configs)
-            meta_data = { "instance-id": "i-#{machine.id.split('-').join}" }
+            meta_data = { "instance-id" => "i-#{machine.id.split('-').join}" }
 
             write_cfg_iso(machine, env, user_data, meta_data)
           end
@@ -97,7 +97,7 @@ module Vagrant
               source_dir = Pathname.new(Dir.mktmpdir(TEMP_PREFIX))
               File.open("#{source_dir}/user-data", 'w') { |file| file.write(user_data.to_s) }
 
-              File.open("#{source_dir}/meta-data", 'w') { |file| file.write(meta_data.to_s) }
+              File.open("#{source_dir}/meta-data", 'w') { |file| file.write(meta_data.to_yaml) }
 
               iso_path = env[:env].host.capability(:create_iso,
                                                    source_dir, volume_id: "cidata")
diff --git a/test/unit/vagrant/action/builtin/cloud_init_setup_test.rb b/test/unit/vagrant/action/builtin/cloud_init_setup_test.rb
index 232859751..40607d849 100644
--- a/test/unit/vagrant/action/builtin/cloud_init_setup_test.rb
+++ b/test/unit/vagrant/action/builtin/cloud_init_setup_test.rb
@@ -25,7 +25,7 @@ describe Vagrant::Action::Builtin::CloudInitSetup do
   let(:text_cfgs) { [MIME::Text.new("data: true", "cloud-config"),
                      MIME::Text.new("data: false", "cloud-config") ] }
 
-  let(:meta_data) { { "instance-id": "i-123456789" } }
+  let(:meta_data) { { "instance-id" => "i-123456789" } }
 
 
   let(:subject) { described_class.new(app, env) }
@@ -96,6 +96,11 @@ describe Vagrant::Action::Builtin::CloudInitSetup do
   describe "#write_cfg_iso" do
     let(:iso_path) { Pathname.new("fake/iso/path") }
     let(:source_dir) { Pathname.new("fake/source/path") }
+    let(:meta_data_file) { double("meta_data_file") }
+
+    before do
+      allow(meta_data_file).to receive(:write).and_return(true)
+    end
 
     it "raises an error if the host capability is not supported" do
       message = subject.generate_cfg_msg(machine, text_cfgs)
@@ -109,12 +114,13 @@ describe Vagrant::Action::Builtin::CloudInitSetup do
       allow(host).to receive(:capability?).with(:create_iso).and_return(true)
       allow(Dir).to receive(:mktmpdir).and_return(source_dir)
       expect(File).to receive(:open).with("#{source_dir}/user-data", 'w').and_return(true)
-      expect(File).to receive(:open).with("#{source_dir}/meta-data", 'w').and_return(true)
+      expect(File).to receive(:open).with("#{source_dir}/meta-data", 'w').and_yield(meta_data_file)
       expect(FileUtils).to receive(:remove_entry).with(source_dir).and_return(true)
       allow(host).to receive(:capability).with(:create_iso, source_dir, volume_id: "cidata").and_return(iso_path)
       expect(vm.disks).to receive(:each)
+      expect(meta_data).to receive(:to_yaml)
 
-      subject.write_cfg_iso(machine, env, message, {})
+      subject.write_cfg_iso(machine, env, message, meta_data)
     end
   end