diff --git a/pysendpulse/pysendpulse.py b/pysendpulse/pysendpulse.py
index 8cc7c22..3d8ece3 100644
--- a/pysendpulse/pysendpulse.py
+++ b/pysendpulse/pysendpulse.py
@@ -450,7 +450,7 @@ def add_campaign(self, from_email, from_name, subject, body, addressbook_id, cam
             'sender_name': from_name,
             'sender_email': from_email,
             'subject': subject,
-            'body': base64.b64encode(body),
+            'body': base64.b64encode(body.encode('utf-8')).decode('utf-8'),
             'list_id': addressbook_id,
             'name': campaign_name,
             'attachments': json.dumps(attachments)