diff --git a/source/app/controllers/utils.py b/source/app/controllers/utils.py
index 75f3282..7ccd468 100644
--- a/source/app/controllers/utils.py
+++ b/source/app/controllers/utils.py
@@ -767,7 +767,7 @@ def _cancel_with_cert(invoice, args, auth, certificado):
     pac = PACS[auth['pac']]()
     # ~ info = {'cer': cert.cer_pem, 'key': cert.key_pem, 'pass': '', 'args': args}
     info = {'cer': cert.cer_pem, 'key': cert.key_pem,
-        'key_enc': cert.key_enc, 'pass': cert._p, 'args': args}
+        'key_enc': cert.key_enc, 'pass': cert._p.hex(), 'args': args}
 
     result = pac.cancel(invoice.xml, info, auth)
     if pac.error: