diff --git a/cli.js b/cli.js
index 9eed0b855..a43aedfc9 100755
--- a/cli.js
+++ b/cli.js
@@ -23,6 +23,7 @@ var cli = meow({
 		'Options',
 		'  --init       Add AVA to your project',
 		'  --fail-fast  Stop after first test failure',
+		'  --serial     Run tests serially',
 		'',
 		'Examples',
 		'  ava',
@@ -36,7 +37,7 @@ var cli = meow({
 	]
 }, {
 	string: ['_'],
-	boolean: ['fail-fast']
+	boolean: ['fail-fast', 'serial']
 });
 
 var fileCount = 0;
@@ -96,6 +97,10 @@ function run(file) {
 		args.push('--fail-fast');
 	}
 
+	if (cli.flags.serial) {
+		args.push('--serial');
+	}
+
 	return fork(args)
 		.on('test', test)
 		.on('data', function (data) {
diff --git a/lib/runner.js b/lib/runner.js
index 08227d92b..5a6f8ec43 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -4,6 +4,8 @@ var EventEmitter = require('events').EventEmitter;
 var Promise = require('bluebird');
 var Test = require('./test');
 
+var isSerial = process.argv.indexOf('--serial') !== -1;
+
 function noop() {}
 
 function each(items, fn) {
@@ -105,6 +107,10 @@ Runner.prototype._runTest = function (test) {
 };
 
 Runner.prototype.concurrent = function (tests) {
+	if (isSerial) {
+		return this.serial(tests);
+	}
+
 	return each(tests, this._runTestWithHooks.bind(this));
 };
 
diff --git a/readme.md b/readme.md
index 6e7e2affc..dace9bf0d 100644
--- a/readme.md
+++ b/readme.md
@@ -92,6 +92,7 @@ $ ava --help
   Options
     --init       Add AVA to your project
     --fail-fast  Stop after first test failure
+    --serial     Run tests serially
 
   Examples
     ava
@@ -468,6 +469,14 @@ Have fun!
 
 Running tests concurrently comes with some challenges, doing IO is one. Usually, serial tests just create temp directories in the current test directory and cleans it up at the end. This won't work when you run tests concurrently as tests will conflict with each other. The correct way to do it is to use a new temp directory for each test. The [`tempfile`](https://github.com/sindresorhus/tempfile) and [`temp-write`](https://github.com/sindresorhus/temp-write) modules can be helpful.
 
+### Debugging
+
+AVA runs tests concurrently by default, which is suboptimal when you need to debug something. Instead, run tests serially with the `--serial` option:
+
+```
+$ ava --serial
+```
+
 
 ## FAQ
 
diff --git a/test/fixture/serial.js b/test/fixture/serial.js
new file mode 100644
index 000000000..d4c2f8ea9
--- /dev/null
+++ b/test/fixture/serial.js
@@ -0,0 +1,26 @@
+import test from '../../';
+
+function randomDelay() {
+	return parseInt(Math.random() * 1000, 10);
+}
+
+const tests = [];
+
+test('first', t => {
+	setTimeout(() => {
+		tests.push('first');
+		t.end();
+	}, randomDelay());
+});
+
+test('second', t => {
+	setTimeout(() => {
+		tests.push('second');
+		t.end();
+	}, randomDelay());
+});
+
+test(t => {
+	t.same(tests, ['first', 'second']);
+	t.end();
+});
diff --git a/test/test.js b/test/test.js
index 01b75ff6e..5fec14f09 100644
--- a/test/test.js
+++ b/test/test.js
@@ -839,6 +839,15 @@ test('fail-fast mode', function (t) {
 	});
 });
 
+test('serial execution mode', function (t) {
+	t.plan(1);
+
+	execCli(['fixture/serial.js', '--serial'], function (err) {
+		t.ifError(err);
+		t.end();
+	});
+});
+
 test('power-assert support', function (t) {
 	t.plan(2);
 
@@ -853,6 +862,8 @@ test('power-assert support', function (t) {
 });
 
 test('change process.cwd() to a test\'s directory', function (t) {
+	t.plan(2);
+
 	execCli('fixture/process-cwd.js', function (err, stdout) {
 		t.ifError(err);
 		t.is(stdout.trim(), join(__dirname, 'fixture'));