diff --git a/README.md b/README.md
index 406986a5..a9270fb2 100644
--- a/README.md
+++ b/README.md
@@ -120,6 +120,7 @@ Environment variables (will overwrite other server configs)
 | HMD_USECDN | `true` or `false` | set to use CDN resources or not (default is `true`) |
 | HMD_ALLOW_ANONYMOUS | `true` or `false` | set to allow anonymous usage (default is `true`) |
 | HMD_ALLOW_FREEURL | `true` or `false` | set to allow new note by accessing not exist note url |
+| HMD_DB_URL | `mysql://localhost:3306/database` | set the db url |
 | HMD_FACEBOOK_CLIENTID | no example | Facebook API client id |
 | HMD_FACEBOOK_CLIENTSECRET | no example | Facebook API client secret |
 | HMD_TWITTER_CONSUMERKEY | no example | Twitter API consumer key |
@@ -157,6 +158,7 @@ Server settings `config.json`
 | usecdn | `true` or `false` | set to use CDN resources or not (default is `true`) |
 | allowanonymous | `true` or `false` | set to allow anonymous usage (default is `true`) |
 | allowfreeurl | `true` or `false` | set to allow new note by accessing not exist note url |
+| dburl | `mysql://localhost:3306/database` | set the db url, if set this variable then below db config won't be applied |
 | db | `{ "dialect": "sqlite", "storage": "./db.hackmd.sqlite" }` | set the db configs, [see more here](http://sequelize.readthedocs.org/en/latest/api/sequelize/) |
 | sslkeypath | `./cert/client.key` | ssl key path (only need when you set usessl) |
 | sslcertpath | `./cert/hackmd_io.crt` | ssl cert path (only need when you set usessl) |
diff --git a/lib/config.js b/lib/config.js
index 9e8aa337..f8df0a73 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -24,10 +24,8 @@ var allowanonymous = process.env.HMD_ALLOW_ANONYMOUS ? (process.env.HMD_ALLOW_AN
 var allowfreeurl = process.env.HMD_ALLOW_FREEURL ? (process.env.HMD_ALLOW_FREEURL === 'true') : !!config.allowfreeurl;
 
 // db
-var db = config.db || {
-    dialect: 'sqlite',
-    storage: './db.hackmd.sqlite'
-};
+var dburl = config.dburl || process.env.HMD_DB_URL || process.env.DATABASE_URL;
+var db = config.db || {};
 
 // ssl path
 var sslkeypath = config.sslkeypath || '';
@@ -131,6 +129,7 @@ module.exports = {
     usecdn: usecdn,
     allowanonymous: allowanonymous,
     allowfreeurl: allowfreeurl,
+    dburl: dburl,
     db: db,
     sslkeypath: path.join(cwd, sslkeypath),
     sslcertpath: path.join(cwd, sslcertpath),
diff --git a/lib/models/index.js b/lib/models/index.js
index 6fcffb5f..de6cd13c 100644
--- a/lib/models/index.js
+++ b/lib/models/index.js
@@ -15,8 +15,8 @@ dbconfig.logging = config.debug ? logger.info : false;
 var sequelize = null;
 
 // Heroku specific
-if (process.env.DATABASE_URL)
-    sequelize = new Sequelize(process.env.DATABASE_URL);
+if (config.dburl)
+    sequelize = new Sequelize(config.dburl, dbconfig);
 else
     sequelize = new Sequelize(dbconfig.database, dbconfig.username, dbconfig.password, dbconfig);