diff --git a/ghost/members-api/index.js b/ghost/members-api/index.js
index c200bee2cb..04d0e241f0 100644
--- a/ghost/members-api/index.js
+++ b/ghost/members-api/index.js
@@ -14,7 +14,7 @@ module.exports = function MembersApi({
         publicKey
     },
     auth: {
-        allowSelfSignup,
+        allowSelfSignup = true,
         getSigninURL
     },
     paymentConfig,