diff --git a/greenlock-store-sequelize.js b/greenlock-store-sequelize.js
index 1e80a68..2edd794 100644
--- a/greenlock-store-sequelize.js
+++ b/greenlock-store-sequelize.js
@@ -17,7 +17,7 @@ module.exports.create = function (config={}) {
   else {
     // This library expects config.db to resolve the db object.  We'll ensure
     // that this is the case with the provided db, as it was with the baked-in
-    // db. 
+    // db.
     config.db = Promise.resolve(config.db);
   }
 
@@ -108,7 +108,7 @@ module.exports.create = function (config={}) {
       return db.Keypair.findOne({
         where: {
           // using xid because id is reserved by sequelize
-          xid: opts.certificate.kid || opts.certificate.id || opts.subject
+          xid: (opts.certificate && (opts.certificate.kid || opts.certificate.id)) || opts.subject
         }
       });
     }).then(function (record) {
@@ -131,7 +131,7 @@ module.exports.create = function (config={}) {
       return db.Keypair.findOrCreate({
         where: {
           // using xid because id is reserved by sequelize
-          xid: opts.certificate.kid || opts.certificate.id || opts.subject
+          xid: (opts.certificate && (opts.certificate.kid || opts.certificate.id)) || opts.subject
         }
       });
     }).then(function ([record,created]) {