README.md in ruby_universign-1.5.0 vs README.md in ruby_universign-1.5.1

@@ -57,15 +57,15 @@
   name:    'another.pdf',
   content: File.open('spec/fixtures/universign-guide-8.8.pdf').read
 )
 
 signer = Universign::TransactionSigner.new(
-  first_name:   "Signer's first name",
-  last_name:    "Signer's last name",
-  email:        '[e-mail]',
-  phone_number: '0101010101',
-  success_url:  'https://google.com/',
-  signature:    Universign::SignatureField.new(coordinate: [20, 20], page: 1)
+  first_name:      "Signer's first name",
+  last_name:       "Signer's last name",
+  email:           '[e-mail]',
+  phone_number:    '0101010101',
+  success_url:     'https://google.com/',
+  signature_field: Universign::SignatureField.new(coordinate: [20, 20], page: 1)
 )
 
 transaction = Universign::Transaction.create(
   documents: [document_from_url, document_from_content],
   signers:   [signer],