diff --git a/generators/app/index.js b/generators/app/index.js
index b5fbbde..8c84f2b 100644
--- a/generators/app/index.js
+++ b/generators/app/index.js
@@ -71,6 +71,19 @@ module.exports = yeoman.Base.extend({
         done();
       });
     },
+    isAmbient() {
+      var done = this.async();
+
+      this.prompt({
+        type: 'confirm',
+        name: 'isAmbient',
+        message: `Is this module ambient? i.e. does it declare globally?`,
+        default: true
+      }, (props) => {
+        this.isAmbient = props.isAmbient;
+        done();
+      });
+    },
     username() {
       var done = this.async();
 
@@ -164,9 +177,17 @@ module.exports = yeoman.Base.extend({
       this.fs.write('test/test.ts',
         ['/// <reference path="./main.d.ts" />',
           '',
-          `import * as ${this.sourcePackageName} from '${this.sourcePackageName}';`,
+          this.isAmbient? '': `import * as ${this.sourcePackageName} from '${this.sourcePackageName}';`,
           ''].join('\n'));
     },
+    updatePackageJson() {
+      this.fs.copyTpl(
+        this.templatePath('template/package.json'),
+        this.destinationPath('package.json'),
+        {
+          ambient: this.isAmbient? '--ambient': ''
+        });
+    },
     createLICENSE() {
       var filename = `template/${this.license}.txt`;
       var author = this.nameOnLicense.trim();
diff --git a/generators/app/templates/package.json b/generators/app/templates/template/package.json
similarity index 76%
rename from generators/app/templates/package.json
rename to generators/app/templates/template/package.json
index effe7e2..a799cdb 100644
--- a/generators/app/templates/package.json
+++ b/generators/app/templates/template/package.json
@@ -1,6 +1,6 @@
 {
   "scripts": {
-    "build": "typings bundle -o test",
+    "build": "typings bundle -o test <%- ambient %>",
     "test": "ts-node test/test.ts"
   },
   "private": true,
diff --git a/test/app.js b/test/app.js
index 6e4ec9c..41c7167 100644
--- a/test/app.js
+++ b/test/app.js
@@ -3,36 +3,73 @@ var path = require('path');
 var assert = require('yeoman-assert');
 var helpers = require('yeoman-test');
 
-describe('app', function () {
-  before(function (done) {
-    this.timeout(60000);
-    helpers.run(path.join(__dirname, '../generators/app'))
-      .withPrompts({
-        sourceUri: 'visionmedia/batch',
-        projectUri: 'typed-typings/npm-batch',
-        // Set to false to avoid longer test time.
-        isNpm: false,
-        username: 'unional',
-        license: 'MIT',
-        name: 'unional'
-      })
-      .on('end', done);
+describe('app', function() {
+  describe('module', function() {
+    before(function(done) {
+      this.timeout(60000);
+      helpers.run(path.join(__dirname, '../generators/app'))
+        .withPrompts({
+          sourceUri: 'visionmedia/batch',
+          projectUri: 'typed-typings/npm-batch',
+          // Set to false to avoid longer test time.
+          isNpm: false,
+          isAmbient: false,
+          username: 'unional',
+          license: 'MIT',
+          name: 'unional'
+        })
+        .on('end', done);
+    });
+
+    it('creates files', function() {
+      assert.file([
+        '.vscode/settings.json',
+        'test/test.ts',
+        'test/main.d.ts',
+        'test/browser.d.ts',
+        '.editorconfig',
+        '.gitignore',
+        'LICENSE',
+        'index.d.ts',
+        'README.md',
+        'package.json',
+        'typings.json',
+        'tsconfig.json'
+      ]);
+    });
   });
+  describe('namespace', function() {
+    before(function(done) {
+      this.timeout(60000);
+      helpers.run(path.join(__dirname, '../generators/app'))
+        .withPrompts({
+          sourceUri: 'visionmedia/batch',
+          projectUri: 'typed-typings/npm-batch',
+          // Set to false to avoid longer test time.
+          isNpm: false,
+          isAmbient: true,
+          username: 'unional',
+          license: 'MIT',
+          name: 'unional'
+        })
+        .on('end', done);
+    });
 
-  it('creates files', function () {
-    assert.file([
-      '.vscode/settings.json',
-      'test/test.ts',
-      'test/main.d.ts',
-      'test/browser.d.ts',
-      '.editorconfig',
-      '.gitignore',
-      'LICENSE',
-      'index.d.ts',
-      'README.md',
-      'package.json',
-      'typings.json',
-      'tsconfig.json'
-    ]);
+    it('creates files', function() {
+      assert.file([
+        '.vscode/settings.json',
+        'test/test.ts',
+        'test/main.d.ts',
+        'test/browser.d.ts',
+        '.editorconfig',
+        '.gitignore',
+        'LICENSE',
+        'index.d.ts',
+        'README.md',
+        'package.json',
+        'typings.json',
+        'tsconfig.json'
+      ]);
+    });
   });
 });