diff --git a/source/tests/tests_comercio.py b/source/tests/tests_comercio.py
index 831d9ee..f87fac9 100644
--- a/source/tests/tests_comercio.py
+++ b/source/tests/tests_comercio.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python3
 
+import base64
 import datetime
 import sys
+import time
 import unittest
 import uuid
 import lxml.etree as ET
@@ -15,6 +17,7 @@ from comerciodigital import PACComercioDigital
 
 NAME = 'comercio'
 
+
 TEMPLATE_CFDI = """<cfdi:Comprobante xmlns:cfdi="http://www.sat.gob.mx/cfd/3" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" LugarExpedicion="06850" Moneda="MXN" SubTotal="10000.00" TipoCambio="1" TipoDeComprobante="I" Total="11600.00" FormaPago="01" MetodoPago="PUE" Version="3.3" xsi:schemaLocation="http://www.sat.gob.mx/cfd/3 http://www.sat.gob.mx/sitio_internet/cfd/3/cfdv33.xsd">
   <cfdi:Emisor Rfc="EKU9003173C9" RegimenFiscal="601"/>
   <cfdi:Receptor Rfc="BASM740115RW0" UsoCFDI="G01"/>
@@ -50,8 +53,8 @@ class TestCfdi(object):
         path_cer = Path(path.parent).joinpath('certificados', f'{NAME}.cer')
         path_key = Path(path.parent).joinpath('certificados', f'{NAME}.enc')
         path_xslt = Path(path.parent).joinpath('xslt', 'cadena.xslt')
-        cer = path_cer.read_bytes()
-        key = path_key.read_bytes()
+        self._cer_ori = cer = path_cer.read_bytes()
+        self._key_ori = key = path_key.read_bytes()
 
         self._cert = SATCertificate(cer, key)
         self._doc = ET.parse(BytesIO(TEMPLATE_CFDI.encode()))
@@ -75,6 +78,12 @@ class TestCfdi(object):
         xslt.close()
         return
 
+    @property
+    def cert(self):
+        cer = base64.b64encode(self._cer_ori).decode()
+        key = base64.b64encode(self._key_ori).decode()
+        return key, cer
+
 
 class TestStamp(unittest.TestCase):
 
@@ -90,6 +99,27 @@ class TestStamp(unittest.TestCase):
         self.assertFalse(bool(self.pac.error))
         self.assertTrue(bool(uuid.UUID(cfdi_uuid)))
 
+    def test_cfdi_cancel(self):
+        cfdi = TestCfdi()
+        result = self.pac.stamp(cfdi.xml)
+        cfdi_uuid = self.pac.cfdi_uuid
+
+        self.assertFalse(bool(self.pac.error))
+        self.assertTrue(bool(uuid.UUID(cfdi_uuid)))
+
+        time.sleep(1)
+        cert = cfdi.cert
+        info = {
+            'key': cert[0],
+            'cer': cert[1],
+            'pass': '12345678',
+            'tipo': 'cfdi3.3',
+        }
+        result = self.pac.cancel(result, info)
+
+        self.assertFalse(bool(self.pac.error))
+        self.assertTrue(bool(result))
+
 
 if __name__ == '__main__':
     unittest.main()