diff --git a/spec/tasks/vagrant_spec.rb b/spec/tasks/vagrant_spec.rb
index c294c74..d768c19 100644
--- a/spec/tasks/vagrant_spec.rb
+++ b/spec/tasks/vagrant_spec.rb
@@ -2,6 +2,7 @@
 require 'rspec'
 require 'spec_helper'
 require 'net/ssh'
+require_relative '../../tasks/vagrant'
 
 describe 'vagrant' do
   let(:provider) { 'virtualbox' }
@@ -25,12 +26,11 @@
     allow(File).to receive(:read).with(%r{#{tmpdir}.*\.vagrant}).and_return('some_unique_id')
     allow(Open3).to receive(:capture3).with(%r{vagrant ssh-config}, any_args).and_return(['', '', 0]).once
     allow(Net::SSH).to receive(:start).and_return(true)
-    require_relative '../../tasks/vagrant'
   end
 
   it 'provisions a new vagrant box when action is provision' do
-    expect { vagrant }.to output(%r{"status":"ok"}).to_stdout
-    expect { vagrant }.to output(%r{"platform":"generic/debian10"}).to_stdout
-    expect { vagrant }.to output(%r{"role":"worker1"}).to_stdout
+    expect { vagrant }.to raise_error(SystemExit).and output(
+      include('"status":"ok"', '"platform":"generic/debian10"', '"role":"worker1"'),
+    ).to_stdout
   end
 end
diff --git a/tasks/vagrant.rb b/tasks/vagrant.rb
index 439dafc..bdff1de 100755
--- a/tasks/vagrant.rb
+++ b/tasks/vagrant.rb
@@ -205,43 +205,47 @@ def tear_down(node_name, inventory)
   { status: 'ok' }
 end
 
-params = JSON.parse($stdin.read)
-warn params
-platform = params['platform']
-action = params['action']
-node_name = params['node_name']
-vars = params['vars']
-inventory = InventoryHelper.open(params['inventory'])
-enable_synced_folder = params['enable_synced_folder'].nil? ? ENV.fetch('VAGRANT_ENABLE_SYNCED_FOLDER', nil) : params['enable_synced_folder']
-enable_synced_folder = enable_synced_folder.casecmp('true').zero? if enable_synced_folder.is_a?(String)
-provider            = params['provider'].nil? ? ENV.fetch('VAGRANT_PROVIDER', nil) : params['provider']
-cpus                = params['cpus'].nil? ? ENV.fetch('VAGRANT_CPUS', nil) : params['cpus']
-memory              = params['memory'].nil? ? ENV.fetch('VAGRANT_MEMORY', nil) : params['memory']
-hyperv_vswitch      = params['hyperv_vswitch'].nil? ? ENV.fetch('VAGRANT_HYPERV_VSWITCH', nil) : params['hyperv_vswitch']
-hyperv_smb_username = params['hyperv_smb_username'].nil? ? ENV.fetch('VAGRANT_HYPERV_SMB_USERNAME', nil) : params['hyperv_smb_username']
-hyperv_smb_password = params['hyperv_smb_password'].nil? ? ENV.fetch('VAGRANT_HYPERV_SMB_PASSWORD', nil) : params['hyperv_smb_password']
-box_url             = params['box_url'].nil? ? ENV.fetch('VAGRANT_BOX_URL', nil) : params['box_url']
-password            = params['password'].nil? ? ENV.fetch('VAGRANT_PASSWORD', nil) : params['password']
-raise 'specify a node_name when tearing down' if action == 'tear_down' && node_name.nil?
-raise 'specify a platform when provisioning' if action == 'provision' && platform.nil?
-
-unless node_name.nil? ^ platform.nil?
-  case action
-  when 'tear_down'
-    raise 'specify only a node_name, not platform, when tearing down'
-  when 'provision'
-    raise 'specify only a platform, not node_name, when provisioning'
-  else
-    raise 'specify only one of: node_name, platform'
+def vagrant
+  params = JSON.parse($stdin.read)
+  warn params
+  platform = params['platform']
+  action = params['action']
+  node_name = params['node_name']
+  vars = params['vars']
+  inventory = InventoryHelper.open(params['inventory'])
+  enable_synced_folder = params['enable_synced_folder'].nil? ? ENV.fetch('VAGRANT_ENABLE_SYNCED_FOLDER', nil) : params['enable_synced_folder']
+  enable_synced_folder = enable_synced_folder.casecmp('true').zero? if enable_synced_folder.is_a?(String)
+  provider            = params['provider'].nil? ? ENV.fetch('VAGRANT_PROVIDER', nil) : params['provider']
+  cpus                = params['cpus'].nil? ? ENV.fetch('VAGRANT_CPUS', nil) : params['cpus']
+  memory              = params['memory'].nil? ? ENV.fetch('VAGRANT_MEMORY', nil) : params['memory']
+  hyperv_vswitch      = params['hyperv_vswitch'].nil? ? ENV.fetch('VAGRANT_HYPERV_VSWITCH', nil) : params['hyperv_vswitch']
+  hyperv_smb_username = params['hyperv_smb_username'].nil? ? ENV.fetch('VAGRANT_HYPERV_SMB_USERNAME', nil) : params['hyperv_smb_username']
+  hyperv_smb_password = params['hyperv_smb_password'].nil? ? ENV.fetch('VAGRANT_HYPERV_SMB_PASSWORD', nil) : params['hyperv_smb_password']
+  box_url             = params['box_url'].nil? ? ENV.fetch('VAGRANT_BOX_URL', nil) : params['box_url']
+  password            = params['password'].nil? ? ENV.fetch('VAGRANT_PASSWORD', nil) : params['password']
+  raise 'specify a node_name when tearing down' if action == 'tear_down' && node_name.nil?
+  raise 'specify a platform when provisioning' if action == 'provision' && platform.nil?
+
+  unless node_name.nil? ^ platform.nil?
+    case action
+    when 'tear_down'
+      raise 'specify only a node_name, not platform, when tearing down'
+    when 'provision'
+      raise 'specify only a platform, not node_name, when provisioning'
+    else
+      raise 'specify only one of: node_name, platform'
+    end
   end
-end
 
-begin
-  result = provision(platform, inventory, enable_synced_folder, provider, cpus, memory, hyperv_vswitch, hyperv_smb_username, hyperv_smb_password, box_url, password, vars) if action == 'provision'
-  result = tear_down(node_name, inventory) if action == 'tear_down'
-  puts result.to_json
-  exit 0
-rescue StandardError => e
-  puts({ _error: { kind: 'provision/vagrant_failure', msg: e.message } }.to_json)
-  exit 1
+  begin
+    result = provision(platform, inventory, enable_synced_folder, provider, cpus, memory, hyperv_vswitch, hyperv_smb_username, hyperv_smb_password, box_url, password, vars) if action == 'provision'
+    result = tear_down(node_name, inventory) if action == 'tear_down'
+    puts result.to_json
+    exit 0
+  rescue StandardError => e
+    puts({ _error: { kind: 'provision/vagrant_failure', msg: e.message } }.to_json)
+    exit 1
+  end
 end
+
+vagrant if __FILE__ == $PROGRAM_NAME