diff --git a/lib/api/2fa/webauthn.js b/lib/api/2fa/webauthn.js
index f6cbc87d..9cbbac1c 100644
--- a/lib/api/2fa/webauthn.js
+++ b/lib/api/2fa/webauthn.js
@@ -201,7 +201,7 @@ module.exports = (db, server, userHandler) => {
                             'Indicates whether authenticators should be part of the OS ("platform"), or can be roaming authenticators ("cross-platform")'
                         ),
 
-                    rpId: Joi.string().hostname().empty('Relaying party ID. Is domain.'),
+                    rpId: Joi.string().hostname().empty('').description('Relaying party ID. Is domain.'),
 
                     sess: sessSchema,
                     ip: sessIPSchema
@@ -317,7 +317,7 @@ module.exports = (db, server, userHandler) => {
                         .required()
                         .description('Attestation object represented as a hex string'),
 
-                    rpId: Joi.string().hostname().empty('Relaying Party ID. Is domain'),
+                    rpId: Joi.string().hostname().empty('').description('Relaying party ID. Is domain.'),
 
                     sess: sessSchema,
                     ip: sessIPSchema