diff --git a/index.js b/index.js
index 19db892..c6b8be9 100644
--- a/index.js
+++ b/index.js
@@ -119,7 +119,12 @@ RedisStore.prototype.get = function *(sid) {
     return null;
   }
   try {
-    return JSON.parse(data.toString());
+    var sess = JSON.parse(data.toString());
+    //if ttl ,reset it
+    if(sess.ttl){
+      this.client.expire(sid,sess.ttl);
+    }
+    return sess.sess;
   } catch (err) {
     // ignore err
     debug('parse session error: %s', err.message);
@@ -130,12 +135,15 @@ RedisStore.prototype.set = function *(sid, sess, ttl) {
   if (typeof ttl === 'number') {
     ttl = Math.ceil(ttl / 1000);
   }
-  sess = JSON.stringify(sess);
+  // sess = JSON.stringify(sess);
   if (ttl) {
     debug('SETEX %s %s %s', sid, ttl, sess);
+    //save ttl
+    sess = JSON.stringify({ttl:ttl,sess:sess});
     yield this.client.setex(sid, ttl, sess);
   } else {
     debug('SET %s %s', sid, sess);
+    sess = JSON.stringify({sess:sess});
     yield this.client.set(sid, sess);
   }
   debug('SET %s complete', sid);
diff --git a/test/koa-redis.test.js b/test/koa-redis.test.js
index 362eea9..cf2be7e 100644
--- a/test/koa-redis.test.js
+++ b/test/koa-redis.test.js
@@ -54,7 +54,7 @@ describe('test/koa-redis.test.js', function () {
     client = redisWrapper(client);
     yield store.set('key:db1', {a: 2});
     (yield store.get('key:db1')).should.eql({a: 2});
-    JSON.parse(yield client.get('key:db1')).should.eql({a: 2});
+    JSON.parse(yield client.get('key:db1')).sess.should.eql({a: 2});
     yield store.destroy('key:db1');
     should.not.exist(yield store.get('key:db1'));
     should.not.exist(yield client.get('key:db1'));