diff --git a/HISTORY.md b/HISTORY.md
index 6ffd9a6..12450d4 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,3 +1,8 @@
+unreleased
+==========
+
+  * Change `digits` argument to an `options` argument
+
 2.0.1 / 2014-08-10
 ==================
 
diff --git a/README.md b/README.md
index 0df4814..598ecb9 100644
--- a/README.md
+++ b/README.md
@@ -20,11 +20,18 @@ $ npm install response-time
 var responseTime = require('response-time')
 ```
 
-### responseTime(digits)
+### responseTime(options)
 
 Returns middleware that adds a `X-Response-Time` header to responses.
 
-- `digits` - the fixed number of digits to include. (default: `3`)
+#### Options
+
+`responseTime` accepts these properties in the options object.
+
+##### digits
+
+The fixed number of digits to include in the output, which is always in
+milliseconds, defaults to `3` (ex: `2.300ms`).
 
 ## Examples
 
diff --git a/index.js b/index.js
index 5b0b3d6..105568d 100644
--- a/index.js
+++ b/index.js
@@ -10,6 +10,7 @@
  * Module dependencies
  */
 
+var deprecate = require('depd')('response-time')
 var onHeaders = require('on-headers')
 
 /**
@@ -18,15 +19,25 @@ var onHeaders = require('on-headers')
  * Adds the `X-Response-Time` header displaying the response
  * duration in milliseconds.
  *
- * @param {number} [digits=3]
+ * @param {object} [options]
+ * @param {number} [options.digits=3]
  * @return {function}
  * @api public
  */
 
-module.exports = function responseTime(digits) {
-  digits = digits === undefined
-    ? 3
-    : digits
+module.exports = function responseTime(options) {
+  if (typeof options === 'number') {
+    // back-compat single number argument
+    deprecate('number argument: use {digits: ' + JSON.stringify(options) + '} instead')
+    options = { digits: options }
+  }
+
+  options = options || {}
+
+  // response time digits
+  var digits = options.digits !== undefined
+    ? options.digits
+    : 3
 
   return function responseTime(req, res, next) {
     var startAt = process.hrtime()
diff --git a/package.json b/package.json
index e972c0e..6a84d90 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   "license": "MIT",
   "repository": "expressjs/response-time",
   "dependencies": {
+    "depd": "0.4.5",
     "on-headers": "~1.0.0"
   },
   "devDependencies": {
diff --git a/test/test.js b/test/test.js
index 977614e..eef9bf1 100644
--- a/test/test.js
+++ b/test/test.js
@@ -1,3 +1,6 @@
+
+process.env.NO_DEPRECATION = 'response-time'
+
 var http = require('http');
 var request = require('supertest');
 var responseTime = require('..')
@@ -28,6 +31,13 @@ describe('responseTime()', function () {
       .expect('X-Response-Time', /^[0-9]+\.[0-9]{3}ms$/, done)
     })
 
+    it('should allow custom digits', function (done) {
+      var server = createServer(5)
+      request(server)
+      .get('/')
+      .expect('X-Response-Time', /^[0-9]+\.[0-9]{5}ms$/, done)
+    })
+
     it('should allow no digits', function (done) {
       var server = createServer(0)
       request(server)
@@ -37,8 +47,33 @@ describe('responseTime()', function () {
   })
 })
 
-function createServer(digits, fn) {
-  var _responseTime = responseTime(digits)
+describe('responseTime(options)', function () {
+  describe('with "digits" option', function () {
+    it('should default to 3', function (done) {
+      var server = createServer()
+      request(server)
+      .get('/')
+      .expect('X-Response-Time', /^[0-9]+\.[0-9]{3}ms$/, done)
+    })
+
+    it('should allow custom digits', function (done) {
+      var server = createServer({ digits: 5 })
+      request(server)
+      .get('/')
+      .expect('X-Response-Time', /^[0-9]+\.[0-9]{5}ms$/, done)
+    })
+
+    it('should allow no digits', function (done) {
+      var server = createServer({ digits: 0 })
+      request(server)
+      .get('/')
+      .expect('X-Response-Time', /^[0-9]+ms$/, done)
+    })
+  })
+})
+
+function createServer(opts, fn) {
+  var _responseTime = responseTime(opts)
   return http.createServer(function (req, res) {
     _responseTime(req, res, function (err) {
       setTimeout(function () {