diff --git a/browserid/lib/wsapi.js b/browserid/lib/wsapi.js
index 7ea76cc9358861cafb0c53b1c9f419be65fe0cc3..5fe7a297583dc8f2ada6a3f9155b05337c8bed02 100644
--- a/browserid/lib/wsapi.js
+++ b/browserid/lib/wsapi.js
@@ -280,7 +280,7 @@ function setup(app) {
       } else {
         // same account, we add the key
         db.addKeyToEmail(req.session.authenticatedUser, req.body.email, req.body.pubkey, function (rv) {
-          resp.json(rv);
+          resp.json(rv === undefined);
         });
       }
     });