diff --git a/.babelrc b/.babelrc
deleted file mode 100644
index c13c5f6..0000000
--- a/.babelrc
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "presets": ["es2015"]
-}
diff --git a/.travis.yml b/.travis.yml
index dd43cd3..f441e71 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,17 +1,8 @@
-sudo: false
 language: node_js
 node_js:
-  - "0.10"
-  - "0.11"
-  - "0.12"
-  - "iojs-1"
-  - "iojs-2"
-  - "iojs-3"
-  - "4"
-matrix:
-  allow_failures:
-    - node_js:
-      - "0.11"
-      - "iojs-1"
-      - "iojs-2"
-      - "iojs-3"
+    - "4"
+    - "5"
+    - "6"
+    - "7"
+sudo: false
+script: "npm test"
\ No newline at end of file
diff --git a/gulpfile.js b/gulpfile.js
index 19cbd71..0a19fd7 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -26,7 +26,6 @@
 
 var gulp = require('gulp'),
     mocha = require('gulp-mocha'),
-    babel = require('gulp-babel'),
     git = require('gulp-git'),
     bump = require('gulp-bump'),
     filter = require('gulp-filter'),
@@ -38,10 +37,6 @@ var gulp = require('gulp'),
     eslint = require('gulp-eslint'),
     fs = require('fs');
 
-require('babel-register')({
-    only: /eslint-scope\/(src|test)\//
-});
-
 var TEST = [ 'test/*.js' ];
 var SOURCE = [ 'src/**/*.js' ];
 
@@ -68,23 +63,7 @@ var ESLINT_OPTION = {
     }
 };
 
-var BABEL_OPTIONS = JSON.parse(fs.readFileSync('.babelrc', { encoding: 'utf8' }));
-
-var build = lazypipe()
-    .pipe(sourcemaps.init)
-    .pipe(babel, BABEL_OPTIONS)
-    .pipe(sourcemaps.write)
-    .pipe(gulp.dest, 'lib');
-
-gulp.task('build-for-watch', function () {
-    return gulp.src(SOURCE).pipe(plumber()).pipe(build());
-});
-
-gulp.task('build', function () {
-    return gulp.src(SOURCE).pipe(build());
-});
-
-gulp.task('test', [ 'lint', 'build' ], function () {
+gulp.task('test', function () {
     return gulp.src(TEST)
         .pipe(mocha({
             reporter: 'spec',
@@ -92,10 +71,6 @@ gulp.task('test', [ 'lint', 'build' ], function () {
         }));
 });
 
-gulp.task('watch', [ 'build-for-watch' ], function () {
-    gulp.watch(SOURCE, [ 'build-for-watch' ]);
-});
-
 // Currently, not works for ES6.
 gulp.task('lint', function () {
     return gulp.src(SOURCE)
@@ -135,9 +110,9 @@ function inc(importance) {
         }));
 }
 
-gulp.task('patch', [ 'build' ], function () { return inc('patch'); })
-gulp.task('minor', [ 'build' ], function () { return inc('minor'); })
-gulp.task('major', [ 'build' ], function () { return inc('major'); })
+gulp.task('patch', function () { return inc('patch'); })
+gulp.task('minor', function () { return inc('minor'); })
+gulp.task('major', function () { return inc('major'); })
 
 gulp.task('travis', [ 'test' ]);
-gulp.task('default', [ 'travis' ]);
+gulp.task('default', [ 'travis' ]);
\ No newline at end of file
diff --git a/package.json b/package.json
index fe019d1..b2772e1 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "eslint-scope",
   "description": "ECMAScript scope analyzer for ESLint",
   "homepage": "http://github.com/eslint/eslint-scope",
-  "main": "lib/index.js",
+  "main": "src/index.js",
   "version": "3.6.0",
   "engines": {
     "node": ">=0.4.0"
@@ -29,15 +29,11 @@
     "estraverse": "^4.1.1"
   },
   "devDependencies": {
-    "babel": "^6.3.26",
-    "babel-preset-es2015": "^6.3.13",
-    "babel-register": "^6.3.13",
     "chai": "^3.4.1",
     "eslint-release": "^0.10.1",
     "espree": "^3.1.1",
     "esprima": "^2.7.1",
     "gulp": "^3.9.0",
-    "gulp-babel": "^6.1.1",
     "gulp-bump": "^1.0.0",
     "gulp-eslint": "^1.1.1",
     "gulp-espower": "^1.0.2",
diff --git a/src/definition.js b/src/definition.js
index faef938..54ee3c6 100644
--- a/src/definition.js
+++ b/src/definition.js
@@ -21,13 +21,14 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+"use strict";
 
-import Variable from './variable';
+const Variable = require('./variable');
 
 /**
  * @class Definition
  */
-export default class Definition {
+class Definition {
     constructor(type, name, node, parent, index, kind) {
         /**
          * @member {String} Definition#type - type of the occurrence (e.g. "Parameter", "Variable", ...).
@@ -70,9 +71,9 @@ class ParameterDefinition extends Definition {
     }
 }
 
-export {
+module.exports = {
     ParameterDefinition,
     Definition
-}
+};
 
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/index.js b/src/index.js
index a345e1c..320dfd8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -45,17 +45,18 @@
  * The main interface is the {@link analyze} function.
  * @module escope
  */
+"use strict";
 
 /*jslint bitwise:true */
 
-import assert from 'assert';
+const assert = require('assert');
 
-import ScopeManager from './scope-manager';
-import Referencer from './referencer';
-import Reference from './reference';
-import Variable from './variable';
-import Scope from './scope';
-import { version } from '../package.json';
+const ScopeManager = require('./scope-manager');
+const Referencer = require('./referencer');
+const Reference = require('./reference');
+const Variable = require('./variable');
+const Scope = require('./scope');
+const version = require('../package.json').version;
 
 function defaultOptions() {
     return {
@@ -114,7 +115,7 @@ function updateDeeply(target, override) {
  * @param {string} [providedOptions.fallback='iteration'] - A kind of the fallback in order to encounter with unknown node. See [esrecurse](https://github.com/estools/esrecurse)'s the `fallback` option.
  * @return {ScopeManager}
  */
-export function analyze(tree, providedOptions) {
+function analyze(tree, providedOptions) {
     var scopeManager, referencer, options;
 
     options = updateDeeply(defaultOptions(), providedOptions);
@@ -129,7 +130,7 @@ export function analyze(tree, providedOptions) {
     return scopeManager;
 }
 
-export {
+module.exports = {
     /** @name module:escope.version */
     version,
     /** @name module:escope.Reference */
@@ -139,7 +140,8 @@ export {
     /** @name module:escope.Scope */
     Scope,
     /** @name module:escope.ScopeManager */
-    ScopeManager
+    ScopeManager,
+    analyze
 };
 
 
diff --git a/src/pattern-visitor.js b/src/pattern-visitor.js
index b98e98a..bd4bcb7 100644
--- a/src/pattern-visitor.js
+++ b/src/pattern-visitor.js
@@ -21,15 +21,16 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+"use strict";
 
-import { Syntax } from 'estraverse';
-import esrecurse from 'esrecurse';
+const Syntax = require('estraverse').Syntax;
+const esrecurse = require('esrecurse');
 
 function getLast(xs) {
     return xs[xs.length - 1] || null;
 }
 
-export default class PatternVisitor extends esrecurse.Visitor {
+class PatternVisitor extends esrecurse.Visitor {
     static isPattern(node) {
         var nodeType = node.type;
         return (
@@ -131,4 +132,6 @@ export default class PatternVisitor extends esrecurse.Visitor {
     }
 }
 
+module.exports = PatternVisitor;
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/reference.js b/src/reference.js
index 7f273a3..8775440 100644
--- a/src/reference.js
+++ b/src/reference.js
@@ -21,6 +21,7 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+"use strict";
 
 const READ = 0x1;
 const WRITE = 0x2;
@@ -30,7 +31,7 @@ const RW = READ | WRITE;
  * A Reference represents a single occurrence of an identifier in code.
  * @class Reference
  */
-export default class Reference {
+class Reference {
     constructor(ident, scope, flag,  writeExpr, maybeImplicitGlobal, partial, init) {
         /**
          * Identifier syntax node.
@@ -151,4 +152,6 @@ Reference.WRITE = WRITE;
  */
 Reference.RW = RW;
 
+module.exports = Reference;
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/referencer.js b/src/referencer.js
index bd81080..3cbf6d4 100644
--- a/src/referencer.js
+++ b/src/referencer.js
@@ -21,13 +21,18 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-import { Syntax } from 'estraverse';
-import esrecurse from 'esrecurse';
-import Reference from './reference';
-import Variable from './variable';
-import PatternVisitor from './pattern-visitor';
-import { ParameterDefinition, Definition } from './definition';
-import assert from 'assert';
+"use strict";
+
+const Syntax = require('estraverse').Syntax;
+const esrecurse = require('esrecurse');
+const Reference = require('./reference');
+const Variable = require('./variable');
+const PatternVisitor = require('./pattern-visitor');
+const definition = require('./definition');
+const assert = require('assert');
+
+const ParameterDefinition = definition.ParameterDefinition;
+const Definition = definition.Definition;
 
 function traverseIdentifierInPattern(options, rootPattern, referencer, callback) {
     // Call the callback at left hand identifier nodes, and Collect right hand nodes.
@@ -90,7 +95,7 @@ class Importer extends esrecurse.Visitor {
 }
 
 // Referencing variables and creating bindings.
-export default class Referencer extends esrecurse.Visitor {
+class Referencer extends esrecurse.Visitor {
     constructor(options, scopeManager) {
         super(null, options);
         this.options = options;
@@ -581,4 +586,6 @@ export default class Referencer extends esrecurse.Visitor {
     }
 }
 
+module.exports = Referencer;
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/scope-manager.js b/src/scope-manager.js
index 024535d..90578f4 100644
--- a/src/scope-manager.js
+++ b/src/scope-manager.js
@@ -21,29 +21,28 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
-
-import WeakMap from 'es6-weak-map';
-import Scope from './scope';
-import assert from 'assert';
-
-import {
-    GlobalScope,
-    CatchScope,
-    WithScope,
-    ModuleScope,
-    ClassScope,
-    SwitchScope,
-    FunctionScope,
-    ForScope,
-    TDZScope,
-    FunctionExpressionNameScope,
-    BlockScope
-} from './scope';
+"use strict";
+
+const WeakMap = require('es6-weak-map');
+const Scope = require('./scope');
+const assert = require('assert');
+
+const GlobalScope = Scope.GlobalScope;
+const CatchScope = Scope.CatchScope;
+const WithScope = Scope.WithScope;
+const ModuleScope = Scope.ModuleScope;
+const ClassScope = Scope.ClassScope;
+const SwitchScope = Scope.SwitchScope;
+const FunctionScope = Scope.FunctionScope;
+const ForScope = Scope.ForScope;
+const TDZScope = Scope.TDZScope;
+const FunctionExpressionNameScope = Scope.FunctionExpressionNameScope;
+const BlockScope = Scope.BlockScope;
 
 /**
  * @class ScopeManager
  */
-export default class ScopeManager {
+class ScopeManager {
     constructor(options) {
         this.scopes = [];
         this.globalScope = null;
@@ -242,4 +241,6 @@ export default class ScopeManager {
     }
 }
 
+module.exports = ScopeManager;
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/scope.js b/src/scope.js
index 0e4d8c2..988b2d4 100644
--- a/src/scope.js
+++ b/src/scope.js
@@ -21,14 +21,15 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+"use strict";
 
-import { Syntax } from 'estraverse';
-import Map from 'es6-map';
+const Syntax = require('estraverse').Syntax;
+const Map = require('es6-map');
 
-import Reference from './reference';
-import Variable from './variable';
-import Definition from './definition';
-import assert from 'assert';
+const Reference = require('./reference');
+const Variable = require('./variable');
+const Definition = require('./definition').Definition;
+const assert = require('assert');
 
 function isStrictScope(scope, block, isMethodDefinition, useDirective) {
     var body, i, iz, stmt, expr;
@@ -125,7 +126,7 @@ function shouldBeStatically(def) {
 /**
  * @class Scope
  */
-export default class Scope {
+class Scope {
     constructor(scopeManager, type, upperScope, block, isMethodDefinition) {
         /**
          * One of 'TDZ', 'module', 'block', 'switch', 'function', 'catch', 'with', 'function', 'class', 'global'.
@@ -458,7 +459,7 @@ export default class Scope {
     }
 }
 
-export class GlobalScope extends Scope {
+class GlobalScope extends Scope {
     constructor(scopeManager, block) {
         super(scopeManager, 'global', null, block, false);
         this.implicit = {
@@ -514,13 +515,13 @@ export class GlobalScope extends Scope {
     }
 }
 
-export class ModuleScope extends Scope {
+class ModuleScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'module', upperScope, block, false);
     }
 }
 
-export class FunctionExpressionNameScope extends Scope {
+class FunctionExpressionNameScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'function-expression-name', upperScope, block, false);
         this.__define(block.id,
@@ -536,13 +537,13 @@ export class FunctionExpressionNameScope extends Scope {
     }
 }
 
-export class CatchScope extends Scope {
+class CatchScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'catch', upperScope, block, false);
     }
 }
 
-export class WithScope extends Scope {
+class WithScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'with', upperScope, block, false);
     }
@@ -563,25 +564,25 @@ export class WithScope extends Scope {
     }
 }
 
-export class TDZScope extends Scope {
+class TDZScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'TDZ', upperScope, block, false);
     }
 }
 
-export class BlockScope extends Scope {
+class BlockScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'block', upperScope, block, false);
     }
 }
 
-export class SwitchScope extends Scope {
+class SwitchScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'switch', upperScope, block, false);
     }
 }
 
-export class FunctionScope extends Scope {
+class FunctionScope extends Scope {
     constructor(scopeManager, upperScope, block, isMethodDefinition) {
         super(scopeManager, 'function', upperScope, block, isMethodDefinition);
 
@@ -632,16 +633,31 @@ export class FunctionScope extends Scope {
     }
 }
 
-export class ForScope extends Scope {
+ class ForScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'for', upperScope, block, false);
     }
 }
 
-export class ClassScope extends Scope {
+class ClassScope extends Scope {
     constructor(scopeManager, upperScope, block) {
         super(scopeManager, 'class', upperScope, block, false);
     }
 }
 
+module.exports = {
+    Scope,
+    GlobalScope,
+    ModuleScope,
+    FunctionExpressionNameScope,
+    CatchScope,
+    WithScope,
+    TDZScope,
+    BlockScope,
+    SwitchScope,
+    FunctionScope,
+    ForScope,
+    ClassScope
+};
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/src/variable.js b/src/variable.js
index 3945b38..40435e6 100644
--- a/src/variable.js
+++ b/src/variable.js
@@ -21,13 +21,14 @@
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
+"use strict";
 
 /**
  * A Variable represents a locally scoped identifier. These include arguments to
  * functions.
  * @class Variable
  */
-export default class Variable {
+class Variable {
     constructor(name, scope) {
         /**
          * The variable name, as given in the source code.
@@ -78,4 +79,6 @@ Variable.ImportBinding = 'ImportBinding';
 Variable.TDZ = 'TDZ';
 Variable.ImplicitGlobalVariable = 'ImplicitGlobalVariable';
 
+module.exports = Variable;
+
 /* vim: set sw=4 ts=4 et tw=80 : */
diff --git a/test/arguments.js b/test/arguments.js
index 2e32a43..73c2d95 100644
--- a/test/arguments.js
+++ b/test/arguments.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import esprima from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const esprima = require('esprima');
+const analyze = require('..').analyze;
 
 describe('arguments', function() {
     it('arguments are correctly materialized', function() {
diff --git a/test/catch-scope.js b/test/catch-scope.js
index 0e05e3c..cd4f58c 100644
--- a/test/catch-scope.js
+++ b/test/catch-scope.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import esprima from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const esprima = require('esprima');
+const analyze = require('..').analyze;
 
 describe('catch', function() {
     it('creates scope', function() {
diff --git a/test/child-visitor-keys.js b/test/child-visitor-keys.js
index c8d7095..49d39ad 100644
--- a/test/child-visitor-keys.js
+++ b/test/child-visitor-keys.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import esprima from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const esprima = require('esprima');
+const analyze = require('..').analyze;
 
 describe('childVisitorKeys option', function() {
     it('should handle as a known node if the childVisitorKeys option was given.', function() {
diff --git a/test/es6-arrow-function-expression.js b/test/es6-arrow-function-expression.js
index af0a687..5f99f89 100644
--- a/test/es6-arrow-function-expression.js
+++ b/test/es6-arrow-function-expression.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 arrow function expression', function() {
     it('materialize scope for arrow function expression', function() {
diff --git a/test/es6-block-scope.js b/test/es6-block-scope.js
index 861cee8..79c4971 100644
--- a/test/es6-block-scope.js
+++ b/test/es6-block-scope.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 block scope', function() {
     it('let is materialized in ES6 block scope#1', function() {
diff --git a/test/es6-catch.js b/test/es6-catch.js
index f05a4a6..c7bf5a5 100644
--- a/test/es6-catch.js
+++ b/test/es6-catch.js
@@ -20,9 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+"use strict";
+
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 catch', function() {
     it('takes binding pattern', function() {
diff --git a/test/es6-class.js b/test/es6-class.js
index 8c6ffac..78d5029 100644
--- a/test/es6-class.js
+++ b/test/es6-class.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 class', function() {
     it('declaration name creates class scope', function() {
diff --git a/test/es6-default-parameters.js b/test/es6-default-parameters.js
index 96f1765..18339a4 100644
--- a/test/es6-default-parameters.js
+++ b/test/es6-default-parameters.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('ES6 default parameters:', function() {
     describe('a default parameter creates a writable reference for its initialization:', function() {
diff --git a/test/es6-destructuring-assignments.js b/test/es6-destructuring-assignments.js
index 0d894c7..dcdbb92 100644
--- a/test/es6-destructuring-assignments.js
+++ b/test/es6-destructuring-assignments.js
@@ -20,11 +20,12 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import harmony from '../third_party/esprima';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const harmony = require('../third_party/esprima');
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('ES6 destructuring assignments', function() {
     it('Pattern in var in ForInStatement', function() {
@@ -713,7 +714,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(4);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'a',
             'b',
             'c',
@@ -797,7 +798,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(4);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'a',
             'b',
             'rest',
@@ -838,7 +839,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(6);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'a',
             'b',
             'c',
@@ -886,7 +887,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(4);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'a',
             'b',
             'obj',
@@ -933,7 +934,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(4);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'shorthand',
             'value',
             'world',
@@ -982,7 +983,7 @@ describe('ES6 destructuring assignments', function() {
         expect(scope.variables).to.have.length(0);
         expect(scope.references).to.have.length(0);
         expect(scope.implicit.left).to.have.length(8);
-        expect(scope.implicit.left.map(({ identifier }) => identifier.name)).to.deep.equal([
+        expect(scope.implicit.left.map((left) => left.identifier.name)).to.deep.equal([
             'shorthand',
             'a',
             'b',
diff --git a/test/es6-export.js b/test/es6-export.js
index 018e7ec..6e7edca 100644
--- a/test/es6-export.js
+++ b/test/es6-export.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('export declaration', function() {
     // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-static-and-runtme-semantics-module-records
diff --git a/test/es6-import.js b/test/es6-import.js
index 48e996b..9b15e02 100644
--- a/test/es6-import.js
+++ b/test/es6-import.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('import declaration', function() {
     // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-static-and-runtme-semantics-module-records
diff --git a/test/es6-iteration-scope.js b/test/es6-iteration-scope.js
index d1957e7..123eb7d 100644
--- a/test/es6-iteration-scope.js
+++ b/test/es6-iteration-scope.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 iteration scope', function() {
     it('let materialize iteration scope for ForInStatement#1', function() {
diff --git a/test/es6-new-target.js b/test/es6-new-target.js
index 029a31f..a31d5a1 100644
--- a/test/es6-new-target.js
+++ b/test/es6-new-target.js
@@ -20,9 +20,10 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const analyze = require('..').analyze;
 
 const parse = require('../third_party/espree');
 
diff --git a/test/es6-object.js b/test/es6-object.js
index 0fd7623..12dfc68 100644
--- a/test/es6-object.js
+++ b/test/es6-object.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 object', function() {
     it('method definition', function() {
diff --git a/test/es6-rest-args.js b/test/es6-rest-args.js
index 89ff2da..3a6165a 100644
--- a/test/es6-rest-args.js
+++ b/test/es6-rest-args.js
@@ -20,11 +20,12 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse as esprima } from '../third_party/esprima';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const esprima = require('../third_party/esprima').parse;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('ES6 rest arguments', function() {
     it('materialize rest argument in scope (esprima: rest property of FunctionDeclaration)', function() {
diff --git a/test/es6-super.js b/test/es6-super.js
index 4da988d..0ff5221 100644
--- a/test/es6-super.js
+++ b/test/es6-super.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 super', function() {
     it('is not handled as reference', function() {
diff --git a/test/es6-switch.js b/test/es6-switch.js
index e32061a..217d214 100644
--- a/test/es6-switch.js
+++ b/test/es6-switch.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 switch', function() {
     it('materialize scope', function() {
diff --git a/test/es6-template-literal.js b/test/es6-template-literal.js
index 113f795..a5127f4 100644
--- a/test/es6-template-literal.js
+++ b/test/es6-template-literal.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('ES6 template literal', function() {
     it('refer variables', function() {
diff --git a/test/fallback.js b/test/fallback.js
index 0cd001c..574c813 100644
--- a/test/fallback.js
+++ b/test/fallback.js
@@ -20,10 +20,12 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
+
+const expect = require('chai').expect;
+const esprima = require('../third_party/esprima');
+const analyze = require('..').analyze;
 
-import { expect } from 'chai';
-import esprima from 'esprima';
-import { analyze } from '..';
 
 describe('fallback option', function() {
     it('should raise an error when it encountered an unknown node if no fallback.', function() {
diff --git a/test/function-expression-name.js b/test/function-expression-name.js
index e488b83..e720c44 100644
--- a/test/function-expression-name.js
+++ b/test/function-expression-name.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse as parse } from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('function name', function() {
     it('should create its special scope', function() {
diff --git a/test/get-declared-variables.js b/test/get-declared-variables.js
index ef0e227..004b315 100644
--- a/test/get-declared-variables.js
+++ b/test/get-declared-variables.js
@@ -20,11 +20,12 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { visit } from 'esrecurse';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const visit = require('esrecurse').visit;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('ScopeManager.prototype.getDeclaredVariables', function() {
     const verify = (ast, type, expectedNamesList) => {
diff --git a/test/global-increment.js b/test/global-increment.js
index b613473..83f77b3 100644
--- a/test/global-increment.js
+++ b/test/global-increment.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('global increment', function() {
     it('becomes read/write', function() {
diff --git a/test/implicit-global-reference.js b/test/implicit-global-reference.js
index 291560b..a9e04bf 100644
--- a/test/implicit-global-reference.js
+++ b/test/implicit-global-reference.js
@@ -19,11 +19,11 @@
 // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-
-import { expect } from 'chai';
-import { analyze } from '..';
-import { parse } from 'esprima';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('implicit global reference', function() {
     it('assignments global scope', function() {
@@ -32,7 +32,7 @@ describe('implicit global reference', function() {
             x = 300;
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.defs.map(def => def.type)))).to.be.eql(
             [
@@ -53,7 +53,7 @@ describe('implicit global reference', function() {
             x = 300;
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.defs.map(def => def.type)))).to.be.eql(
             [
@@ -77,7 +77,7 @@ describe('implicit global reference', function() {
             }
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.defs.map(def => def.type)))).to.be.eql(
             [
@@ -103,7 +103,7 @@ describe('implicit global reference', function() {
             }
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
@@ -133,7 +133,7 @@ describe('implicit global reference', function() {
             }
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
@@ -161,7 +161,7 @@ describe('implicit global reference', function() {
                 for (x in y) { }
             }`);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
@@ -191,7 +191,7 @@ describe('implicit global reference', function() {
             }
         `);
 
-        const { scopes } = analyze(ast);
+        const scopes = analyze(ast).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
diff --git a/test/implied-strict.js b/test/implied-strict.js
index f415e15..148241b 100644
--- a/test/implied-strict.js
+++ b/test/implied-strict.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('impliedStrict option', function() {
     it('ensures all user scopes are strict if ecmaVersion >= 5', function() {
diff --git a/test/label.js b/test/label.js
index 6b67f89..95e6b30 100644
--- a/test/label.js
+++ b/test/label.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('label', function() {
     it('should not create variables', function() {
diff --git a/test/nodejs-scope.js b/test/nodejs-scope.js
index 2ea861e..dff2c11 100644
--- a/test/nodejs-scope.js
+++ b/test/nodejs-scope.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from '../third_party/esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('nodejsScope option', function() {
     it('creates a function scope following the global scope immediately', function() {
diff --git a/test/object-expression.js b/test/object-expression.js
index f36e28c..d8ad451 100644
--- a/test/object-expression.js
+++ b/test/object-expression.js
@@ -1,5 +1,7 @@
-import { expect } from 'chai';
-import { analyze } from '..';
+"use strict";
+
+const expect = require('chai').expect;
+const analyze = require('..').analyze;
 
 describe('object expression', function() {
     it('doesn\'t require property type', function() {
diff --git a/test/optimistic.js b/test/optimistic.js
index 4144d04..450dabb 100644
--- a/test/optimistic.js
+++ b/test/optimistic.js
@@ -19,11 +19,11 @@
 // ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-
-import { expect } from 'chai';
-import { analyze } from '..';
-import { parse } from 'esprima';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('optimistic', function() {
     it('direct call to eval', function() {
@@ -37,7 +37,7 @@ describe('optimistic', function() {
             }
         `);
 
-        const { scopes } = analyze(ast, {optimistic: true});
+        const scopes = analyze(ast, {optimistic: true}).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
@@ -67,7 +67,7 @@ describe('optimistic', function() {
             }
         `);
 
-        const { scopes } = analyze(ast, {optimistic: true});
+        const scopes = analyze(ast, {optimistic: true}).scopes;
 
         expect(scopes.map(scope => scope.variables.map(variable => variable.name))).to.be.eql(
             [
diff --git a/test/references.js b/test/references.js
index 5de08f7..2972d9a 100644
--- a/test/references.js
+++ b/test/references.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import espree from '../third_party/espree';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const espree = require('../third_party/espree');
+const analyze = require('..').analyze;
 
 describe('References:', function() {
     describe('When there is a `let` declaration on global,', function() {
@@ -554,7 +555,7 @@ describe('References:', function() {
                 expect(scope.variables).to.have.length.of.at.least(1);
                 expect(scope.variables[0].name).to.equal('a');
 
-                const { references } = scope.variables[0];
+                const references = scope.variables[0].references;
                 expect(references).to.have.length.of.at.least(1);
 
                 references.forEach(reference => {
diff --git a/test/with-scope.js b/test/with-scope.js
index 5dc93f2..d526c01 100644
--- a/test/with-scope.js
+++ b/test/with-scope.js
@@ -20,10 +20,11 @@
 //  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 //  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 //  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"use strict";
 
-import { expect } from 'chai';
-import { parse } from 'esprima';
-import { analyze } from '..';
+const expect = require('chai').expect;
+const parse = require('../third_party/esprima').parse;
+const analyze = require('..').analyze;
 
 describe('with', function() {
     it('creates scope', function() {