diff --git a/api.js b/api.js
index e13a7c41c..a96503b37 100644
--- a/api.js
+++ b/api.js
@@ -6,7 +6,7 @@ var fs = require('fs');
 var flatten = require('arr-flatten');
 var Promise = require('bluebird');
 var figures = require('figures');
-var assign = require('object-assign');
+var objectAssign = require('object-assign');
 var globby = require('globby');
 var chalk = require('chalk');
 var fork = require('./lib/fork');
@@ -18,7 +18,8 @@ function Api(files, options) {
 
 	EventEmitter.call(this);
 
-	assign(this, options);
+	objectAssign(this, options);
+	this.options = options;
 
 	this.rejectionCount = 0;
 	this.exceptionCount = 0;
@@ -40,23 +41,7 @@ util.inherits(Api, EventEmitter);
 module.exports = Api;
 
 Api.prototype._runFile = function (file) {
-	var args = [file];
-
-	if (this.failFast) {
-		args.push('--fail-fast');
-	}
-
-	if (this.serial) {
-		args.push('--serial');
-	}
-
-	// Forward the `time-require` `--sorted` flag.
-	// Intended for internal optimization tests only.
-	if (this._sorted) {
-		args.push('--sorted');
-	}
-
-	return fork(args)
+	return fork(file, this.options)
 		.on('stats', this._handleStats)
 		.on('test', this._handleTest)
 		.on('unhandledRejections', this._handleRejections)
@@ -162,7 +147,7 @@ Api.prototype.run = function () {
 					if (++statsCount === self.fileCount) {
 						self.emit('ready');
 
-						var method = self.serial ? 'mapSeries' : 'map';
+						var method = self.options.serial ? 'mapSeries' : 'map';
 
 						deferred.resolve(Promise[method](files, function (file, index) {
 							return tests[index].run();
diff --git a/index.js b/index.js
index cf0ed5d54..31d7153bb 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,5 @@
 'use strict';
 var relative = require('path').relative;
-var hasFlag = require('has-flag');
 var chalk = require('chalk');
 var serializeError = require('serialize-error');
 var globals = require('./lib/globals');
@@ -8,11 +7,13 @@ var Runner = require('./lib/runner');
 var send = require('./lib/send');
 var log = require('./lib/logger');
 
-var runner = new Runner();
-
 // note that test files have require('ava')
 require('./lib/babel').avaRequired = true;
 
+var opts = JSON.parse(process.argv[2]);
+
+var runner = new Runner(opts);
+
 // check if the test is being run without AVA cli
 var isForked = typeof process.send === 'function';
 
@@ -45,7 +46,7 @@ function test(props) {
 
 	send('test', props);
 
-	if (props.error && hasFlag('fail-fast')) {
+	if (props.error && opts.failFast) {
 		isFailed = true;
 		exit();
 	}
diff --git a/lib/babel.js b/lib/babel.js
index cbf8f2b72..dcb7d3456 100644
--- a/lib/babel.js
+++ b/lib/babel.js
@@ -2,7 +2,14 @@
 
 var debug = require('debug')('ava');
 
+var opts = JSON.parse(process.argv[2]);
+
 if (debug.enabled) {
+	// Forward the `time-require` `--sorted` flag.
+	// Intended for internal optimization tests only.
+	if (opts._sorted) {
+		process.argv.push('--sorted');
+	}
 	require('time-require');
 }
 
@@ -31,7 +38,7 @@ var hasGenerator = require('has-generator');
 var serializeError = require('serialize-error');
 var send = require('./send');
 
-var testPath = process.argv[2];
+var testPath = opts.file;
 
 // include local babel and fallback to ava's babel
 var babel;
diff --git a/lib/fork.js b/lib/fork.js
index 806ecd01b..d0f66446b 100644
--- a/lib/fork.js
+++ b/lib/fork.js
@@ -1,23 +1,22 @@
 'use strict';
 var childProcess = require('child_process');
 var path = require('path');
+var objectAssign = require('object-assign');
 var Promise = require('bluebird');
 var debug = require('debug')('ava');
 var send = require('./send');
 
-module.exports = function (args) {
-	if (!Array.isArray(args)) {
-		args = [args];
-	}
-
+module.exports = function (file, opts) {
 	var filepath = path.join(__dirname, 'babel.js');
-	var file = args[0];
+	opts = objectAssign({file: file}, opts);
 
 	var options = {
 		cwd: path.dirname(file),
 		stdio: ['ignore', process.stderr, process.stderr]
 	};
 
+	var args = [JSON.stringify(opts)];
+
 	var ps = childProcess.fork(filepath, args, options);
 
 	var promise = new Promise(function (resolve, reject) {
diff --git a/lib/runner.js b/lib/runner.js
index 293347d5f..8de51def9 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -2,7 +2,6 @@
 var EventEmitter = require('events').EventEmitter;
 var util = require('util');
 var Promise = require('bluebird');
-var hasFlag = require('has-flag');
 var Test = require('./test');
 var Hook = require('./hook');
 var objectAssign = require('object-assign');
@@ -24,6 +23,8 @@ function Runner(opts) {
 
 	EventEmitter.call(this);
 
+	this.options = opts || {};
+
 	this.results = [];
 	this.tests = [];
 
@@ -130,7 +131,7 @@ Runner.prototype._runTest = function (test) {
 };
 
 Runner.prototype._runConcurrent = function (tests) {
-	if (hasFlag('serial')) {
+	if (this.options.serial) {
 		return this._runSerial(tests);
 	}
 
diff --git a/package.json b/package.json
index 41e83b348..71c31bb09 100644
--- a/package.json
+++ b/package.json
@@ -92,7 +92,6 @@
     "figures": "^1.4.0",
     "fn-name": "^2.0.0",
     "globby": "^4.0.0",
-    "has-flag": "^1.0.0",
     "has-generator": "^1.0.0",
     "is-generator-fn": "^1.0.0",
     "is-observable": "^0.1.0",