diff --git a/bin/nyc.js b/bin/nyc.js
index d2d837d9c..8918a3503 100755
--- a/bin/nyc.js
+++ b/bin/nyc.js
@@ -17,42 +17,38 @@ var wrapper = require.resolve('./wrap.js')
 // we keep these values in a few different forms,
 // used in the various execution contexts of nyc:
 // reporting, instrumenting subprocesses, etc.
-var yargs = configUtil.decorateYargs(configUtil.buildYargs())
+var yargs = configUtil.addCommandsAndHelp(configUtil.buildYargs())
 var instrumenterArgs = processArgs.hideInstrumenteeArgs()
 var argv = yargs.parse(instrumenterArgs)
-var config = configUtil.loadConfig(instrumenterArgs)
 
 if (argv._[0] === 'report') {
-  // run a report.
-  process.env.NYC_CWD = process.cwd()
-
-  report(config)
+  // look in lib/commands/report.js for logic.
 } else if (argv._[0] === 'check-coverage') {
-  checkCoverage(config)
+  // look in lib/commands/check-coverage.js for logic.
 } else if (argv._[0] === 'instrument') {
   // look in lib/commands/instrument.js for logic.
 } else if (argv._.length) {
   // if instrument is set to false,
   // enable a noop instrumenter.
-  if (!config.instrument) config.instrumenter = './lib/instrumenters/noop'
-  else config.instrumenter = './lib/instrumenters/istanbul'
+  if (!argv.instrument) argv.instrumenter = './lib/instrumenters/noop'
+  else argv.instrumenter = './lib/instrumenters/istanbul'
 
-  var nyc = (new NYC(config))
-  if (config.clean) {
+  var nyc = (new NYC(argv))
+  if (argv.clean) {
     nyc.reset()
   } else {
     nyc.createTempDirectory()
   }
-  if (config.all) nyc.addAllFiles()
+  if (argv.all) nyc.addAllFiles()
 
   var env = {
-    NYC_CONFIG: JSON.stringify(config),
+    NYC_CONFIG: JSON.stringify(argv),
     NYC_CWD: process.cwd(),
     NYC_ROOT_ID: nyc.rootId,
-    NYC_INSTRUMENTER: config.instrumenter
+    NYC_INSTRUMENTER: argv.instrumenter
   }
 
-  if (config['babel-cache'] === false) {
+  if (argv['babel-cache'] === false) {
     // babel's cache interferes with some configurations, so is
     // disabled by default. opt in by setting babel-cache=true.
     env.BABEL_DISABLE_CACHE = process.env.BABEL_DISABLE_CACHE = '1'
@@ -71,13 +67,13 @@ if (argv._[0] === 'report') {
   ), function (done) {
     var mainChildExitCode = process.exitCode
 
-    if (config.checkCoverage) {
-      checkCoverage(config)
+    if (argv.checkCoverage) {
+      checkCoverage(argv)
       process.exitCode = process.exitCode || mainChildExitCode
-      if (!config.silent) report(config)
+      if (!argv.silent) report(argv)
       return done()
     } else {
-      if (!config.silent) report(config)
+      if (!argv.silent) report(argv)
       return done()
     }
   })
diff --git a/lib/commands/check-coverage.js b/lib/commands/check-coverage.js
new file mode 100644
index 000000000..c12667bbe
--- /dev/null
+++ b/lib/commands/check-coverage.js
@@ -0,0 +1,46 @@
+var NYC
+try {
+  NYC = require('../../index.covered.js')
+} catch (e) {
+  NYC = require('../../index.js')
+}
+
+exports.command = 'check-coverage'
+
+exports.describe = 'check whether coverage is within thresholds provided'
+
+exports.builder = function (yargs) {
+  yargs
+    .option('branches', {
+      default: 0,
+      description: 'what % of branches must be covered?'
+    })
+    .option('functions', {
+      default: 0,
+      description: 'what % of functions must be covered?'
+    })
+    .option('lines', {
+      default: 90,
+      description: 'what % of lines must be covered?'
+    })
+    .option('statements', {
+      default: 0,
+      description: 'what % of statements must be covered?'
+    })
+    .option('per-file', {
+      default: false,
+      description: 'check thresholds per file'
+    })
+    .example('$0 check-coverage --lines 95', "check whether the JSON in nyc's output folder meets the thresholds provided")
+}
+
+exports.handler = function (argv) {
+  process.env.NYC_CWD = process.cwd()
+
+  ;(new NYC(argv)).checkCoverage({
+    lines: argv.lines,
+    functions: argv.functions,
+    branches: argv.branches,
+    statements: argv.statements
+  }, argv['per-file'])
+}
diff --git a/lib/commands/instrument.js b/lib/commands/instrument.js
index cbf70480e..cf1e97461 100644
--- a/lib/commands/instrument.js
+++ b/lib/commands/instrument.js
@@ -11,7 +11,6 @@ exports.describe = 'instruments a file or a directory tree and writes the instru
 
 exports.builder = function (yargs) {
   return yargs
-    .usage('$0 instrument <input> [output]')
     .option('require', {
       alias: 'i',
       default: [],
diff --git a/lib/commands/report.js b/lib/commands/report.js
new file mode 100644
index 000000000..8289980b9
--- /dev/null
+++ b/lib/commands/report.js
@@ -0,0 +1,39 @@
+var NYC
+try {
+  NYC = require('../../index.covered.js')
+} catch (e) {
+  NYC = require('../../index.js')
+}
+
+exports.command = 'report'
+
+exports.describe = 'run coverage report for .nyc_output'
+
+exports.builder = function (yargs) {
+  return yargs
+    .option('reporter', {
+      alias: 'r',
+      describe: 'coverage reporter(s) to use',
+      default: 'text'
+    })
+    .option('report-dir', {
+      describe: 'directory to output coverage reports in',
+      default: 'coverage'
+    })
+    .option('temp-directory', {
+      describe: 'directory to read raw coverage information from',
+      default: './.nyc_output'
+    })
+    .option('show-process-tree', {
+      describe: 'display the tree of spawned processes',
+      default: false,
+      type: 'boolean'
+    })
+    .example('$0 report --reporter=lcov', 'output an HTML lcov report to ./coverage')
+}
+
+exports.handler = function (argv) {
+  process.env.NYC_CWD = process.cwd()
+  var nyc = new NYC(argv)
+  nyc.report()
+}
diff --git a/lib/config-util.js b/lib/config-util.js
index 3c733e083..54c8804e6 100644
--- a/lib/config-util.js
+++ b/lib/config-util.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const arrify = require('arrify')
 const fs = require('fs')
 const path = require('path')
@@ -7,37 +9,29 @@ const Yargs = require('yargs/yargs')
 
 var Config = {}
 
-// load config from a cascade of sources:
-// * command line arguments
-// * package.json
-// * .nycrc
-Config.loadConfig = function (argv, cwd) {
+function guessCWD (cwd) {
   cwd = cwd || process.env.NYC_CWD || process.cwd()
-  var pkgPath = findUp.sync('package.json', {cwd: cwd})
-  var rcPath = findUp.sync(['.nycrc', '.nycrc.json'], {cwd: cwd})
-  var rcConfig = null
+  const pkgPath = findUp.sync('package.json', {cwd: cwd})
+  if (pkgPath) {
+    cwd = path.dirname(pkgPath)
+  }
+  return cwd
+}
+
+function loadConfig (argv, cwd) {
+  const rcPath = findUp.sync(['.nycrc', '.nycrc.json'], {cwd: cwd})
+  let config = {}
 
   if (rcPath) {
-    rcConfig = JSON.parse(
+    config = JSON.parse(
       fs.readFileSync(rcPath, 'utf-8')
     )
   }
 
-  if (pkgPath) {
-    cwd = path.dirname(pkgPath)
-  }
-
-  var config = Config.buildYargs(cwd)
-  if (rcConfig) config.config(rcConfig)
-  config = config.parse(argv || [])
-
-  // post-hoc, we convert several of the
-  // configuration settings to arrays, providing
-  // a consistent contract to index.js.
-  config.require = arrify(config.require)
-  config.extension = arrify(config.extension)
-  config.exclude = arrify(config.exclude)
-  config.include = arrify(config.include)
+  if (config.require) config.require = arrify(config.require)
+  if (config.extension) config.extension = arrify(config.extension)
+  if (config.exclude) config.exclude = arrify(config.exclude)
+  if (config.include) config.include = arrify(config.include)
 
   return config
 }
@@ -45,56 +39,11 @@ Config.loadConfig = function (argv, cwd) {
 // build a yargs object, omitting any settings
 // that would cause the application to exit early.
 Config.buildYargs = function (cwd) {
+  cwd = guessCWD(cwd)
+  const config = loadConfig()
   return Yargs([])
-    .usage('$0 [command] [options]\n\nrun your tests with the nyc bin to instrument them with coverage')
-    .command('report', 'run coverage report for .nyc_output', function (yargs) {
-      return yargs
-        .usage('$0 report [options]')
-        .option('reporter', {
-          alias: 'r',
-          describe: 'coverage reporter(s) to use',
-          default: 'text'
-        })
-        .option('report-dir', {
-          describe: 'directory to output coverage reports in',
-          default: 'coverage'
-        })
-        .option('temp-directory', {
-          describe: 'directory to read raw coverage information from',
-          default: './.nyc_output'
-        })
-        .option('show-process-tree', {
-          describe: 'display the tree of spawned processes',
-          default: false,
-          type: 'boolean'
-        })
-        .example('$0 report --reporter=lcov', 'output an HTML lcov report to ./coverage')
-    })
-    .command('check-coverage', 'check whether coverage is within thresholds provided', function (yargs) {
-      return yargs
-        .usage('$0 check-coverage [options]')
-        .option('branches', {
-          default: 0,
-          description: 'what % of branches must be covered?'
-        })
-        .option('functions', {
-          default: 0,
-          description: 'what % of functions must be covered?'
-        })
-        .option('lines', {
-          default: 90,
-          description: 'what % of lines must be covered?'
-        })
-        .option('statements', {
-          default: 0,
-          description: 'what % of statements must be covered?'
-        })
-        .option('per-file', {
-          default: false,
-          description: 'check thresholds per file'
-        })
-        .example('$0 check-coverage --lines 95', "check whether the JSON in nyc's output folder meets the thresholds provided")
-    })
+    .usage('$0 [command] [options]')
+    .usage('$0 [options] [bin-to-instrument]')
     .option('reporter', {
       alias: 'r',
       describe: 'coverage reporter(s) to use',
@@ -139,7 +88,7 @@ Config.buildYargs = function (cwd) {
     .option('require', {
       alias: 'i',
       default: [],
-      describe: 'a list of additional modules that nyc should attempt to require in its subprocess, e.g., babel-register, babel-polyfill.',
+      describe: 'a list of additional modules that nyc should attempt to require in its subprocess, e.g., babel-register, babel-polyfill',
       global: false
     })
     .option('eager', {
@@ -240,24 +189,29 @@ Config.buildYargs = function (cwd) {
       default: './.nyc_output',
       global: false
     })
-    .pkgConf('nyc', cwd || process.cwd())
+    .pkgConf('nyc', cwd)
     .example('$0 npm test', 'instrument your tests with coverage')
-    .example('$0 --require babel-core/register npm test', 'instrument your tests with coverage and babel')
+    .example('$0 --require babel-core/register npm test', 'instrument your tests with coverage and transpile with Babel')
     .example('$0 report --reporter=text-lcov', 'output lcov report after running your tests')
     .epilog('visit https://git.io/vHysA for list of available reporters')
-    .boolean('help')
     .boolean('h')
     .boolean('version')
+    .config(config)
+    .help(false)
+    .version(false)
 }
 
-// decorate yargs with all the actions
-// that would make it exit: help, version, command.
-Config.decorateYargs = function (yargs) {
+// we add operations that would make yargs
+// exit post-hoc, allowing for a multi-pass
+// parsing step.
+Config.addCommandsAndHelp = function (yargs) {
   return yargs
     .help('h')
     .alias('h', 'help')
     .version()
+    .command(require('../lib/commands/check-coverage'))
     .command(require('../lib/commands/instrument'))
+    .command(require('../lib/commands/report'))
 }
 
 module.exports = Config
diff --git a/package.json b/package.json
index 03f8c41d3..05d8620ba 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "bundle": "bundle-dependencies update",
-    "pretest": "standard",
+    "posttest": "standard",
     "test": "npm run clean && npm run build && npm run instrument && npm run test-integration && npm run test-mocha && npm run report",
     "clean": "rimraf ./.nyc_output ./node_modules/.cache ./.self_coverage ./test/fixtures/.nyc_output ./test/fixtures/node_modules/.cache *covered.js ./lib/*covered.js",
     "build": "node ./build-tests",
@@ -98,8 +98,8 @@
     "signal-exit": "^3.0.1",
     "spawn-wrap": "^1.3.8",
     "test-exclude": "^4.1.1",
-    "yargs": "^8.0.1",
-    "yargs-parser": "^5.0.0"
+    "yargs": "^10.0.3",
+    "yargs-parser": "^8.0.0"
   },
   "devDependencies": {
     "any-path": "^1.3.0",
diff --git a/test/src/nyc-tap.js b/test/src/nyc-tap.js
index bb57388d5..cf2ce38ae 100644
--- a/test/src/nyc-tap.js
+++ b/test/src/nyc-tap.js
@@ -45,45 +45,42 @@ require('tap').mochaGlobals()
 describe('nyc', function () {
   describe('cwd', function () {
     it('sets cwd to process.cwd() if no environment variable is set', function () {
-      var nyc = new NYC(configUtil.loadConfig())
+      var nyc = new NYC(configUtil.buildYargs().parse())
 
       nyc.cwd.should.eql(process.cwd())
     })
 
     it('uses NYC_CWD environment variable for cwd if it is set', function () {
       process.env.NYC_CWD = path.resolve(__dirname, '../fixtures')
-      var nyc = new NYC(configUtil.loadConfig())
+      var nyc = new NYC(configUtil.buildYargs().parse())
 
       nyc.cwd.should.equal(path.resolve(__dirname, '../fixtures'))
     })
 
     it('will look upwards for package.json from cwd', function () {
-      var nyc = new NYC(configUtil.loadConfig([], __dirname))
+      var nyc = new NYC(configUtil.buildYargs(__dirname).parse())
       nyc.cwd.should.eql(path.join(__dirname, '../..'))
     })
 
-    it('uses --cwd for cwd if it is set (highest priority and no look upwards for package.json) ', function () {
-      var nyc = new NYC(configUtil.loadConfig(['--cwd', __dirname], __dirname))
+    it('uses --cwd for cwd if it is set (highest priority and does not look upwards for package.json) ', function () {
+      var nyc = new NYC(configUtil.buildYargs(__dirname).parse(['--cwd', __dirname]))
       nyc.cwd.should.eql(__dirname)
     })
   })
 
   describe('config', function () {
     it("loads 'exclude' patterns from package.json#nyc", function () {
-      var nyc = new NYC(configUtil.loadConfig([], path.resolve(__dirname, '../fixtures')))
+      var nyc = new NYC(configUtil.buildYargs(path.resolve(__dirname, '../fixtures')).parse())
       nyc.exclude.exclude.length.should.eql(8)
     })
 
     it("loads 'extension' patterns from package.json#nyc", function () {
-      var nyc = new NYC(configUtil.loadConfig([], path.resolve(__dirname, '../fixtures/conf-multiple-extensions')))
+      var nyc = new NYC(configUtil.buildYargs(path.resolve(__dirname, '../fixtures/conf-multiple-extensions')).parse())
       nyc.extensions.length.should.eql(3)
     })
 
     it("ignores 'include' option if it's falsy or []", function () {
-      var nyc1 = new NYC(configUtil.loadConfig(
-        [],
-        path.resolve(__dirname, '../fixtures/conf-empty')
-      ))
+      var nyc1 = new NYC(configUtil.buildYargs(path.resolve(__dirname, '../fixtures/conf-empty')).parse())
 
       nyc1.exclude.include.should.equal(false)
 
@@ -95,7 +92,7 @@ describe('nyc', function () {
     })
 
     it("ignores 'exclude' option if it's falsy", function () {
-      var nyc1 = new NYC(configUtil.loadConfig([], path.resolve(__dirname, '../fixtures/conf-empty')))
+      var nyc1 = new NYC(configUtil.buildYargs(path.resolve(__dirname, '../fixtures/conf-empty')).parse())
       nyc1.exclude.exclude.length.should.eql(11)
     })
 
@@ -109,12 +106,12 @@ describe('nyc', function () {
 
   describe('shouldInstrumentFile', function () {
     it('should exclude appropriately with defaults', function () {
-      var nyc = new NYC(configUtil.loadConfig([
+      var nyc = new NYC(configUtil.buildYargs('/cwd').parse([
         '--exclude=test/**',
         '--exclude=test{,-*}.js',
         '--exclude=**/*.test.js',
         '--exclude=**/__tests__/**'
-      ], '/cwd'))
+      ]))
 
       // nyc always excludes "node_modules/**"
       nyc.exclude.shouldInstrument('/cwd/foo', 'foo').should.equal(true)
@@ -131,7 +128,7 @@ describe('nyc', function () {
     })
 
     it('should exclude appropriately with config.exclude', function () {
-      var nyc = new NYC(configUtil.loadConfig([], fixtures))
+      var nyc = new NYC(configUtil.buildYargs(fixtures).parse())
 
       // fixtures/package.json configures excludes: "blarg", "blerg"
       nyc.exclude.shouldInstrument('blarg', 'blarg').should.equal(false)
@@ -142,31 +139,31 @@ describe('nyc', function () {
     })
 
     it('should exclude outside of the current working directory', function () {
-      var nyc = new NYC(configUtil.loadConfig([], '/cwd/foo/'))
+      var nyc = new NYC(configUtil.buildYargs('/cwd/foo/').parse())
       nyc.exclude.shouldInstrument('/cwd/bar', '../bar').should.equal(false)
     })
 
     it('should not exclude if the current working directory is inside node_modules', function () {
-      var nyc = new NYC(configUtil.loadConfig([], '/cwd/node_modules/foo/'))
+      var nyc = new NYC(configUtil.buildYargs('/cwd/node_modules/foo/').parse())
       nyc.exclude.shouldInstrument('/cwd/node_modules/foo/bar', './bar').should.equal(true)
       nyc.exclude.shouldInstrument('/cwd/node_modules/foo/bar', '.\\bar').should.equal(true)
     })
 
     it('allows files to be explicitly included, rather than excluded', function () {
-      var nyc = new NYC(configUtil.loadConfig(['--include=foo.js'], '/cwd/'))
+      var nyc = new NYC(configUtil.buildYargs('/cwd/').parse(['--include=foo.js']))
 
       nyc.exclude.shouldInstrument('/cwd/foo.js', 'foo.js').should.equal(true)
       nyc.exclude.shouldInstrument('/cwd/index.js', 'index.js').should.equal(false)
     })
 
     it('exclude overrides include', function () {
-      var nyc = new NYC(configUtil.loadConfig([
+      var nyc = new NYC(configUtil.buildYargs('/cwd/').parse([
         '--include=foo.js',
         '--include=test.js',
         '--exclude=**/node_modules/**',
         '--exclude=test/**',
         '--exclude=test{,-*}.js'
-      ], '/cwd/'))
+      ]))
 
       nyc.exclude.shouldInstrument('/cwd/foo.js', 'foo.js').should.equal(true)
       nyc.exclude.shouldInstrument('/cwd/test.js', 'test.js').should.equal(false)
@@ -175,7 +172,7 @@ describe('nyc', function () {
 
   describe('wrap', function () {
     it('wraps modules with coverage counters when they are required', function () {
-      var nyc = new NYC(configUtil.loadConfig())
+      var nyc = new NYC(configUtil.buildYargs().parse())
       nyc.reset()
       nyc.wrap()
 
@@ -192,7 +189,7 @@ describe('nyc', function () {
         // the `require` call to istanbul is deferred, loaded here so it doesn't mess with the hooks callCount
         require('istanbul-lib-instrument')
 
-        var nyc = new NYC(configUtil.loadConfig())
+        var nyc = new NYC(configUtil.buildYargs().parse())
         nyc.reset()
         nyc.wrap()
 
@@ -209,7 +206,7 @@ describe('nyc', function () {
 
     describe('produce source map', function () {
       it('handles stack traces', function () {
-        var nyc = new NYC(configUtil.loadConfig('--produce-source-map'))
+        var nyc = new NYC(configUtil.buildYargs().parse('--produce-source-map'))
         nyc.reset()
         nyc.wrap()
 
@@ -218,22 +215,20 @@ describe('nyc', function () {
       })
 
       it('does not handle stack traces when disabled', function () {
-        var nyc = new NYC(configUtil.loadConfig())
+        var nyc = new NYC(configUtil.buildYargs().parse())
         nyc.reset()
         nyc.wrap()
 
         var check = require('../fixtures/stack-trace')
         check().should.match(/stack-trace.js:1:/)
       })
-
-      // TODO: add test for merge source-map logic.
     })
 
     describe('compile handlers for custom extensions are assigned', function () {
       it('assigns a function to custom extensions', function () {
-        var nyc = new NYC(configUtil.loadConfig([],
+        var nyc = new NYC(configUtil.buildYargs(
           path.resolve(__dirname, '../fixtures/conf-multiple-extensions')
-        ))
+        ).parse())
         nyc.reset()
         nyc.wrap()
 
@@ -248,9 +243,9 @@ describe('nyc', function () {
         // the `require` call to istanbul is deferred, loaded here so it doesn't mess with the hooks callCount
         require('istanbul-lib-instrument')
 
-        var nyc = new NYC(configUtil.loadConfig([],
+        var nyc = new NYC(configUtil.buildYargs(
           path.resolve(__dirname, '../fixtures/conf-multiple-extensions')
-        ))
+        ).parse())
 
         sinon.spy(nyc, '_handleJs')
 
@@ -266,7 +261,7 @@ describe('nyc', function () {
     })
 
     function testSignal (signal, done) {
-      var nyc = (new NYC(configUtil.loadConfig([], fixtures)))
+      var nyc = (new NYC(configUtil.buildYargs(fixtures).parse()))
 
       var proc = spawn(process.execPath, [bin, './' + signal + '.js'], {
         cwd: fixtures,
@@ -294,7 +289,7 @@ describe('nyc', function () {
     })
 
     it('does not output coverage for files that have not been included, by default', function (done) {
-      var nyc = (new NYC(configUtil.loadConfig([], process.cwd())))
+      var nyc = (new NYC(configUtil.buildYargs(process.cwd()).parse()))
       nyc.wrap()
       nyc.reset()
 
@@ -308,7 +303,7 @@ describe('nyc', function () {
 
   describe('report', function () {
     it('allows coverage report to be output in an alternative directory', function (done) {
-      var nyc = new NYC(configUtil.loadConfig(
+      var nyc = new NYC(configUtil.buildYargs().parse(
         ['--report-dir=./alternative-report', '--reporter=lcov']
       ))
       nyc.reset()
@@ -330,7 +325,7 @@ describe('nyc', function () {
 
   describe('addAllFiles', function () {
     it('outputs an empty coverage report for all files that are not excluded', function (done) {
-      var nyc = new NYC(configUtil.loadConfig([], fixtures))
+      var nyc = new NYC(configUtil.buildYargs(fixtures).parse())
       nyc.reset()
       nyc.addAllFiles()
 
@@ -348,7 +343,7 @@ describe('nyc', function () {
 
     it('outputs an empty coverage report for multiple configured extensions', function (done) {
       var cwd = path.resolve(fixtures, './conf-multiple-extensions')
-      var nyc = new NYC(configUtil.loadConfig([], cwd))
+      var nyc = new NYC(configUtil.buildYargs(cwd).parse())
       nyc.reset()
       nyc.addAllFiles()
 
@@ -373,7 +368,7 @@ describe('nyc', function () {
     })
 
     it('tracks coverage appropriately once the file is required', function (done) {
-      var nyc = (new NYC(configUtil.loadConfig([], fixtures)))
+      var nyc = (new NYC(configUtil.buildYargs(fixtures).parse()))
       nyc.reset()
       nyc.wrap()
 
@@ -401,7 +396,7 @@ describe('nyc', function () {
         'utf-8'
       )
 
-      var nyc = (new NYC(configUtil.loadConfig(['--require', './test/fixtures/transpile-hook'], fixtures)))
+      var nyc = (new NYC(configUtil.buildYargs(fixtures).parse(['--require', './test/fixtures/transpile-hook'])))
       nyc.reset()
       nyc.addAllFiles()
 
@@ -426,10 +421,10 @@ describe('nyc', function () {
       'utf-8'
     )
 
-    var nyc = (new NYC(configUtil.loadConfig([
+    var nyc = (new NYC(configUtil.buildYargs(fixtures).parse([
       '--require=./test/fixtures/transpile-hook',
       '--extension=.whatever'
-    ], fixtures)))
+    ])))
 
     nyc.reset()
     nyc.addAllFiles()
@@ -449,7 +444,7 @@ describe('nyc', function () {
 
   describe('cache', function () {
     it('handles collisions', function (done) {
-      var nyc = new NYC(configUtil.loadConfig([], fixtures))
+      var nyc = new NYC(configUtil.buildYargs(fixtures).parse())
       nyc.clearCache()
 
       var args = [bin, process.execPath, './cache-collision-runner.js']