diff --git a/src/middlewared/middlewared/plugins/acme_protocol.py b/src/middlewared/middlewared/plugins/acme_protocol.py
index d95bf19a4a82..72dd9a173e78 100644
--- a/src/middlewared/middlewared/plugins/acme_protocol.py
+++ b/src/middlewared/middlewared/plugins/acme_protocol.py
@@ -171,7 +171,7 @@ def do_create(self, data):
             self._config.datastore,
             {
                 'uri': register.uri,
-                'tos': register.terms_of_service,
+                'tos': register.terms_of_service or '',
                 'new_account_uri': directory.newAccount,
                 'new_nonce_uri': directory.newNonce,
                 'new_order_uri': directory.newOrder,