diff --git a/lemur/plugins/lemur_cryptography/plugin.py b/lemur/plugins/lemur_cryptography/plugin.py
index e3058424..8d483ea5 100644
--- a/lemur/plugins/lemur_cryptography/plugin.py
+++ b/lemur/plugins/lemur_cryptography/plugin.py
@@ -82,7 +82,7 @@ def issue_certificate(csr, options):
     builder = builder.serial_number(int(uuid.uuid4()))
 
     private_key = serialization.load_pem_private_key(
-        bytes(options['authority'].authority_certificate.private_key, 'utf-8'),
+        bytes(str(options['authority'].authority_certificate.private_key).encode('utf-8')),
         password=None,
         backend=default_backend()
     )