diff --git a/source/app/controllers/pacs/cfdi_cert.py b/source/app/controllers/pacs/cfdi_cert.py
index 5af2f57..00ed303 100644
--- a/source/app/controllers/pacs/cfdi_cert.py
+++ b/source/app/controllers/pacs/cfdi_cert.py
@@ -4,6 +4,7 @@ import argparse
 import base64
 import datetime
 import getpass
+import hashlib
 import subprocess
 from pathlib import Path
 
@@ -170,6 +171,7 @@ class SATCertificate(object):
 
         xml_signed = ET.tostring(
             tree, encoding='utf-8', xml_declaration=True).decode()
+        xml_signed = xml_signed.replace("'", '"').replace('utf', 'UTF')
 
         return xml_signed
 
diff --git a/source/app/controllers/utils.py b/source/app/controllers/utils.py
index 92ba094..a698e6f 100644
--- a/source/app/controllers/utils.py
+++ b/source/app/controllers/utils.py
@@ -695,8 +695,8 @@ def cancel_xml_sign(invoice, auth, certificado):
     template = TEMPLATE_CANCEL.format(**data)
     tree = ET.fromstring(template.encode())
     sign_xml = cert.sign_xml(tree)
-
     result = pac.cancel_xml(sign_xml, auth, invoice.xml)
+
     if pac.error:
         data = {'ok': False, 'msg': pac.error, 'row': {}}
         return data
diff --git a/source/app/settings.py b/source/app/settings.py
index c70dd3b..4005397 100644
--- a/source/app/settings.py
+++ b/source/app/settings.py
@@ -286,12 +286,12 @@ TEMPLATE_CANCEL = """<Cancelacion xmlns="http://cancelacfd.sat.gob.mx" xmlns:xsd
     <Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
         <SignedInfo>
             <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
-            <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
+            <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
             <Reference URI="">
                 <Transforms>
-                    <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
+                    <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
                 </Transforms>
-                <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
+                <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
                 <DigestValue/>
             </Reference>
         </SignedInfo>
@@ -307,5 +307,4 @@ TEMPLATE_CANCEL = """<Cancelacion xmlns="http://cancelacfd.sat.gob.mx" xmlns:xsd
         </KeyInfo>
     </Signature>
 </Cancelacion>
-
 """