diff --git a/README.md b/README.md
index 4694b38..b7266f0 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,34 @@ app.use('/api', api);
 
 ### .use(errorHandler([options]))
 
-Currently no options.
+Can optionally pass an object of options:
+
+- `showStack` -- Boolean, will include the stack trace in response sent to client for errors. The default behavior when no option is set is to show stack traces when `process.env.NODE_ENV !== 'production'`. Setting `showStack` option will override the default behavior. You can check yourself what environment the code is running in, and set the option accordingly:
+
+```js
+var errorHandler = require("api-error-handler");
+
+var api = new express.Router();
+api.get("/users/:userid", function(req, res, next) {});
+
+function shouldShowStack() {
+  var environment = process.env.NODE_ENV;
+  switch (environment) {
+    // no stack for production or testing environment
+    case "production":
+    case "testing":
+      return false;
+    // include stack in dev or when NODE_ENV is not set
+    case "dev":
+    default:
+      return true;
+  }
+}
+
+api.use(errorHandler({ showStack: shouldShowStack() }));
+
+app.use("/api", api);
+```
 
 ### Errors
 
diff --git a/index.js b/index.js
index 2bf606a..96bb9ab 100644
--- a/index.js
+++ b/index.js
@@ -1,9 +1,20 @@
 
 var statuses = require('statuses');
 
-var production = process.env.NODE_ENV === 'production';
+var isProduction = process.env.NODE_ENV === 'production';
+
+module.exports = function (options) {
+	var opts = options || {}
+
+	if (typeof opts.showStack === 'undefined') {
+		// if showStack is not set, or undefined, set it to false when in production
+		// otherwise, if not set and not in production, set it to true
+		opts.showStack = !isProduction
+		}
+	if (typeof opts.showStack !== 'boolean') {
+			throw new Error('Expected boolean value for showStack option')
+		}
 
-module.exports = function () {
   return function apiErrorHandler(err, req, res, next) {
     var status = err.status || err.statusCode || 500;
     if (status < 400) status = 500;
@@ -13,9 +24,7 @@ module.exports = function () {
       status: status
     };
 
-    // show the stacktrace when not in production
-    // TODO: make this an option
-    if (!production) body.stack = err.stack;
+    if (opts.showStack) body.stack = err.stack;
 
     // internal server errors
     if (status >= 500) {
diff --git a/test/dev.test.js b/test/dev.test.js
new file mode 100644
index 0000000..31a53b9
--- /dev/null
+++ b/test/dev.test.js
@@ -0,0 +1,71 @@
+var path = require('path')
+var error = require('http-errors');
+var request = require('supertest');
+var express = require('express');
+var assert = require('assert');
+
+var handler;
+
+describe('Dev behavior', function() {
+	before(function() {
+		// reset the require cache for this module, so we can reset NODE_ENV 
+		delete require.cache[path.join(__dirname, '../index.js')]
+		process.env.NODE_ENV = 'dev'
+		handler = require('..');
+	})
+	it('NODE_ENV !== production', function() {
+		assert.notStrictEqual(process.env.NODE_ENV, 'production')
+	})
+	it('shows stack by default when not in production', function(done) {
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler());
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.notStrictEqual(body.stack, undefined);
+			done()
+			})
+		})
+	it('hides stack when showStack is false', function(done) {
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler({ showStack: false}));
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.equal(body.stack, undefined);
+			done()
+			})
+		})
+	it('shows stack when showStack is true', function(done) {
+		var originalENV = process.env.NODE_ENV
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler({showStack: true}));
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.notStrictEqual(body.stack, undefined);
+			done()
+			})
+		})
+})
diff --git a/test/production.test.js b/test/production.test.js
new file mode 100644
index 0000000..ebb8856
--- /dev/null
+++ b/test/production.test.js
@@ -0,0 +1,72 @@
+var path = require('path')
+var error = require('http-errors');
+var request = require('supertest');
+var express = require('express');
+var assert = require('assert');
+
+var handler
+
+describe('Production behavior', function() {
+
+	before(function() {
+		// reset the require cache for this module, so we can reset NODE_ENV 
+		delete require.cache[path.join(__dirname, '../index.js')]
+		process.env.NODE_ENV = 'production'
+		handler = require('..');
+	})
+	it('NODE_ENV === production', function() {
+		assert.equal(process.env.NODE_ENV, 'production')
+	})
+	it('hides stack by default in production', function(done) {
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler());
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.equal(body.stack, undefined);
+			done()
+			})
+		})
+	it('hides stack when showStack is false', function(done) {
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler({ showStack: false}));
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.equal(body.stack, undefined);
+			done()
+			})
+		})
+	it('shows stack in production when showStack is true', function(done) {
+var app = express();
+    app.use(function (req, res, next) {
+      next(error(401));
+    });
+    app.use(handler({showStack: true}));
+
+    request(app.listen())
+    .get('/')
+    .end(function (err, res) {
+      assert.ifError(err);
+
+      var body = res.body;
+			assert.notStrictEqual(body.stack, undefined);
+			assert.strictEqual(process.env.NODE_ENV, 'production')
+			done()
+			})
+		})
+})
diff --git a/test/test.js b/test/test.js
index 4eb1f93..3afce93 100644
--- a/test/test.js
+++ b/test/test.js
@@ -50,5 +50,18 @@ describe('API Error Handler', function () {
       assert.equal(body.code, 'b');
       done();
     })
-  })
+	})
+	it('throws if showStack is passed with a non boolean value', function() {
+		var app = express();
+		assert.throws(function() {
+			app.use(handler({showStack: null}))
+			})
+		assert.throws(function() {
+			app.use(handler({showStack: function() {return}}))
+			})
+		assert.throws(function() {
+			app.use(handler({showStack: 'dev'}))
+			})
+
+	})
 })