diff --git a/rest.js b/rest.js
index a3e6423..ece9586 100644
--- a/rest.js
+++ b/rest.js
@@ -262,11 +262,14 @@ module.exports.create = function (bigconf, deps, app) {
           }
         };
 
-        return {
-          access_token: require('jsonwebtoken').sign(payload, pem, Object.assign({expiresIn: '1d'}, opts)),
-          refresh_token: require('jsonwebtoken').sign(payload, pem, opts),
-          scope: grant.scope,
-        };
+        var jwt = require('jsonwebtoken');
+        var result = {};
+        result.scope = grant.scope;
+        result.access_token = jwt.sign(payload, pem, Object.assign({expiresIn: req.body.exp || '1d'}, opts));
+        if (req.body.refresh_token) {
+          result.refresh_token = jwt.sign(payload, pem, Object.assign({expiresIn: req.body.refresh_exp}, opts));
+        }
+        return result;
       });
     });