diff --git a/local-cli/bundle/output/unbundle/index.js b/local-cli/bundle/output/unbundle/index.js
index eb34cbbbf17..d3411ca7aac 100644
--- a/local-cli/bundle/output/unbundle/index.js
+++ b/local-cli/bundle/output/unbundle/index.js
@@ -12,7 +12,11 @@ const asIndexedFile = require('./as-indexed-file');
 const asAssets = require('./as-assets');
 
 function buildBundle(packagerClient, requestOptions) {
-  return packagerClient.buildBundle({...requestOptions, unbundle: true});
+  return packagerClient.buildBundle({
+    ...requestOptions,
+    unbundle: true,
+    isolateModuleIDs: true,
+  });
 }
 
 function saveUnbundle(bundle, options, log) {
diff --git a/packager/package.json b/packager/package.json
index 2a88fc01523..36f258d6ce4 100644
--- a/packager/package.json
+++ b/packager/package.json
@@ -1,5 +1,5 @@
 {
-  "version": "0.3.1",
+  "version": "0.3.2",
   "name": "react-native-packager",
   "description": "Build native apps with React!",
   "repository": {
diff --git a/packager/react-packager/src/Bundler/__tests__/Bundler-test.js b/packager/react-packager/src/Bundler/__tests__/Bundler-test.js
index f3d5c952070..33cca05487e 100644
--- a/packager/react-packager/src/Bundler/__tests__/Bundler-test.js
+++ b/packager/react-packager/src/Bundler/__tests__/Bundler-test.js
@@ -128,6 +128,7 @@ describe('Bundler', function() {
         mainModuleId: 'foo',
         dependencies: modules,
         transformOptions,
+        getModuleId: () => 123,
       })
     );
 
@@ -207,7 +208,8 @@ describe('Bundler', function() {
   pit('gets the list of dependencies from the resolver', function() {
     const entryFile = '/root/foo.js';
     return bundler.getDependencies({entryFile, recursive: true}).then(() =>
-      expect(getDependencies).toBeCalledWith(
+      // jest calledWith does not support jasmine.any
+      expect(getDependencies.mock.calls[0].slice(0, -2)).toEqual([
         '/root/foo.js',
         { dev: true, recursive: true },
         { minify: false,
@@ -219,8 +221,7 @@ describe('Bundler', function() {
             projectRoots,
           }
         },
-        undefined,
-      )
+      ])
     );
   });
 
diff --git a/packager/react-packager/src/Bundler/index.js b/packager/react-packager/src/Bundler/index.js
index 2d67fad9045..029846b197f 100644
--- a/packager/react-packager/src/Bundler/index.js
+++ b/packager/react-packager/src/Bundler/index.js
@@ -141,7 +141,6 @@ class Bundler {
       fileWatcher: opts.fileWatcher,
       assetExts: opts.assetExts,
       cache: this._cache,
-      getModuleId: this._getModuleId,
       transformCode:
         (module, code, options) =>
           this._transformer.transformFile(module.path, code, options),
@@ -169,9 +168,9 @@ class Bundler {
     const moduleSystemDeps =
       this._resolver.getModuleSystemDependencies({dev, unbundle});
     return this._bundle({
+      ...options,
       bundle: new Bundle({dev, minify, sourceMapUrl: options.sourceMapUrl}),
       moduleSystemDeps,
-      ...options,
     });
   }
 
@@ -247,9 +246,10 @@ class Bundler {
     unbundle,
     entryModuleOnly,
     resolutionResponse,
+    isolateModuleIDs,
   }) {
     const onResolutionResponse = response => {
-      bundle.setMainModuleId(this._getModuleId(getMainModule(response)));
+      bundle.setMainModuleId(response.getModuleId(getMainModule(response)));
       if (bundle.setNumPrependedModules) {
         bundle.setNumPrependedModules(
           response.numPrependedDependencies + moduleSystemDeps.length
@@ -273,7 +273,7 @@ class Bundler {
           ? runBeforeMainModule
               .map(name => modulesByName[name])
               .filter(Boolean)
-              .map(this._getModuleId, this)
+              .map(response.getModuleId)
           : undefined;
 
         bundle.finalize({
@@ -294,6 +294,7 @@ class Bundler {
       resolutionResponse,
       onResolutionResponse,
       finalizeBundle,
+      isolateModuleIDs,
     });
   }
 
@@ -344,6 +345,7 @@ class Bundler {
     hot,
     unbundle,
     resolutionResponse,
+    isolateModuleIDs,
     onResolutionResponse = noop,
     onModuleTransformed = noop,
     finalizeBundle = noop,
@@ -371,6 +373,7 @@ class Bundler {
         hot,
         onProgress,
         minify,
+        isolateModuleIDs,
         generateSourceMaps: unbundle,
       });
     }
@@ -398,6 +401,7 @@ class Bundler {
           bundle,
           entryFilePath,
           transformOptions: response.transformOptions,
+          getModuleId: response.getModuleId,
         }).then(transformed => {
           modulesByName[transformed.name] = module;
           onModuleTransformed({
@@ -467,6 +471,7 @@ class Bundler {
     hot = false,
     recursive = true,
     generateSourceMaps = false,
+    isolateModuleIDs = false,
     onProgress,
   }) {
     return this.getTransformOptions(
@@ -491,6 +496,7 @@ class Bundler {
         {dev, platform, recursive},
         transformOptions,
         onProgress,
+        isolateModuleIDs ? createModuleIdFactory() : this._getModuleId,
       );
     });
   }
@@ -527,13 +533,14 @@ class Bundler {
     );
   }
 
-  _toModuleTransport({module, bundle, entryFilePath, transformOptions}) {
+  _toModuleTransport({module, bundle, entryFilePath, transformOptions, getModuleId}) {
     let moduleTransport;
     if (module.isAsset_DEPRECATED()) {
-      moduleTransport = this._generateAssetModule_DEPRECATED(bundle, module);
+      moduleTransport =
+        this._generateAssetModule_DEPRECATED(bundle, module, getModuleId);
     } else if (module.isAsset()) {
       moduleTransport = this._generateAssetModule(
-        bundle, module, transformOptions.platform);
+        bundle, module, getModuleId, transformOptions.platform);
     }
 
     if (moduleTransport) {
@@ -554,7 +561,7 @@ class Bundler {
 
       return new ModuleTransport({
         name,
-        id: this._getModuleId(module),
+        id: getModuleId(module),
         code,
         map,
         meta: {dependencies, dependencyOffsets, preloaded},
@@ -568,7 +575,7 @@ class Bundler {
     return this._resolver.getDebugInfo();
   }
 
-  _generateAssetModule_DEPRECATED(bundle, module) {
+  _generateAssetModule_DEPRECATED(bundle, module, getModuleId) {
     return Promise.all([
       sizeOf(module.path),
       module.getName(),
@@ -588,7 +595,7 @@ class Bundler {
 
       return new ModuleTransport({
         name: id,
-        id: this._getModuleId(module),
+        id: getModuleId(module),
         code: code,
         sourceCode: code,
         sourcePath: module.path,
@@ -647,7 +654,7 @@ class Bundler {
   }
 
 
-  _generateAssetModule(bundle, module, platform = null) {
+  _generateAssetModule(bundle, module, getModuleId, platform = null) {
     return Promise.all([
       module.getName(),
       this._generateAssetObjAndCode(module, platform),
@@ -655,7 +662,7 @@ class Bundler {
       bundle.addAsset(asset);
       return new ModuleTransport({
         name,
-        id: this._getModuleId(module),
+        id: getModuleId(module),
         code,
         meta: meta,
         sourceCode: code,
diff --git a/packager/react-packager/src/Resolver/__tests__/Resolver-test.js b/packager/react-packager/src/Resolver/__tests__/Resolver-test.js
index 3d89226d38a..6473ee3cc7f 100644
--- a/packager/react-packager/src/Resolver/__tests__/Resolver-test.js
+++ b/packager/react-packager/src/Resolver/__tests__/Resolver-test.js
@@ -50,6 +50,7 @@ describe('Resolver', function() {
     constructor({dependencies, mainModuleId}) {
       this.dependencies = dependencies;
       this.mainModuleId = mainModuleId;
+      this.getModuleId = createGetModuleId();
     }
 
     prependDependency(dependency) {
@@ -95,7 +96,7 @@ describe('Resolver', function() {
 
       DependencyGraph.prototype.getDependencies.mockImplementation(
         () => Promise.reject());
-      new Resolver({projectRoot: '/root', })
+      new Resolver({projectRoot: '/root'})
         .getDependencies(entry, {platform}, transformOptions);
       expect(DependencyGraph.prototype.getDependencies).toBeCalledWith({
         entryPath: entry,
@@ -110,7 +111,6 @@ describe('Resolver', function() {
       var deps = [module];
 
       var depResolver = new Resolver({
-        getModuleId: createGetModuleId(),
         projectRoot: '/root',
       });
 
@@ -121,8 +121,14 @@ describe('Resolver', function() {
         }));
       });
 
-      return depResolver.getDependencies('/root/index.js', { dev: false })
-        .then(function(result) {
+      return depResolver
+        .getDependencies(
+          '/root/index.js',
+          { dev: false },
+          undefined,
+          undefined,
+          createGetModuleId()
+        ).then(function(result) {
           expect(result.mainModuleId).toEqual('index');
           expect(result.dependencies[result.dependencies.length - 1]).toBe(module);
           expect(DependencyGraph.prototype.createPolyfill.mock.calls.map((call) => call[0])).toEqual([
@@ -227,8 +233,14 @@ describe('Resolver', function() {
 
       const polyfill = {};
       DependencyGraph.prototype.createPolyfill.mockReturnValueOnce(polyfill);
-      return depResolver.getDependencies('/root/index.js', { dev: true })
-        .then(function(result) {
+      return depResolver
+        .getDependencies(
+          '/root/index.js',
+          { dev: true },
+          undefined,
+          undefined,
+          createGetModuleId()
+        ).then(function(result) {
           expect(result.mainModuleId).toEqual('index');
           expect(DependencyGraph.mock.instances[0].getDependencies)
               .toBeCalledWith({entryPath: '/root/index.js', recursive: true});
@@ -254,8 +266,14 @@ describe('Resolver', function() {
         }));
       });
 
-      return depResolver.getDependencies('/root/index.js', { dev: false })
-        .then((result) => {
+      return depResolver
+        .getDependencies(
+          '/root/index.js',
+          { dev: false },
+          undefined,
+          undefined,
+          createGetModuleId()
+        ).then((result) => {
           expect(result.mainModuleId).toEqual('index');
           expect(DependencyGraph.prototype.createPolyfill.mock.calls[result.dependencies.length - 2]).toEqual([
             { file: 'some module',
@@ -278,12 +296,10 @@ describe('Resolver', function() {
   });
 
   describe('wrapModule', function() {
-    let depResolver, getModuleId;
+    let depResolver;
     beforeEach(() => {
-      getModuleId = createGetModuleId();
       depResolver = new Resolver({
         depResolver,
-        getModuleId,
         projectRoot: '/root',
       });
     });
@@ -325,7 +341,8 @@ describe('Resolver', function() {
       const moduleIds = new Map(
         resolutionResponse
           .getResolvedDependencyPairs()
-          .map(([importId, module]) => [importId, getModuleId(module)])
+          .map(([importId, module]) =>
+            [importId, resolutionResponse.getModuleId(module)])
       );
 
       return depResolver.wrapModule({
@@ -337,7 +354,7 @@ describe('Resolver', function() {
         dev: false,
       }).then(({code: processedCode}) => {
         expect(processedCode).toEqual([
-          `__d(${getModuleId(module)} /* test module */, function(global, require, module, exports) {` +
+          `__d(${resolutionResponse.getModuleId(module)} /* test module */, function(global, require, module, exports) {` +
           // require
           `require(${moduleIds.get('x')} /* x */)`,
           `require(${moduleIds.get('y')} /* y */)`,
@@ -364,7 +381,7 @@ describe('Resolver', function() {
         dev: true,
       }).then(({code: processedCode}) =>
         expect(processedCode).toEqual([
-          `__d(${getModuleId(module)} /* test module */, function(global, require, module, exports) {` +
+          `__d(${resolutionResponse.getModuleId(module)} /* test module */, function(global, require, module, exports) {` +
             code,
           '}, "test module");'
         ].join('\n'))
@@ -413,7 +430,7 @@ describe('Resolver', function() {
       let depResolver, module, resolutionResponse;
 
       beforeEach(() => {
-        depResolver = new Resolver({getModuleId, projectRoot: '/root'});
+        depResolver = new Resolver({projectRoot: '/root'});
         module = createJsonModule(id);
         resolutionResponse = new ResolutionResponseMock({
           dependencies: [module],
@@ -426,7 +443,7 @@ describe('Resolver', function() {
           .wrapModule({resolutionResponse, module, name: id, code, dev: false})
           .then(({code: processedCode}) =>
             expect(processedCode).toEqual([
-              `__d(${getModuleId(module)} /* ${id} */, function(global, require, module, exports) {`,
+              `__d(${resolutionResponse.getModuleId(module)} /* ${id} */, function(global, require, module, exports) {`,
               `module.exports = ${code}\n});`,
             ].join('')));
       });
@@ -442,7 +459,6 @@ describe('Resolver', function() {
           Promise.resolve({code, map}));
         depResolver = new Resolver({
           projectRoot: '/root',
-          getModuleId,
           minifyCode,
         });
         module = createModule(id);
@@ -455,7 +471,7 @@ describe('Resolver', function() {
       });
 
       pit('should invoke the minifier with the wrapped code', () => {
-        const wrappedCode = `__d(${getModuleId(module)} /* ${id} */, function(global, require, module, exports) {${code}\n});`
+        const wrappedCode = `__d(${resolutionResponse.getModuleId(module)} /* ${id} */, function(global, require, module, exports) {${code}\n});`
         return depResolver
           .wrapModule({
             resolutionResponse,
diff --git a/packager/react-packager/src/Resolver/index.js b/packager/react-packager/src/Resolver/index.js
index 772c067b133..89fd40b96eb 100644
--- a/packager/react-packager/src/Resolver/index.js
+++ b/packager/react-packager/src/Resolver/index.js
@@ -47,10 +47,6 @@ const validateOpts = declareOpts({
     type: 'object',
     required: true,
   },
-  getModuleId: {
-    type: 'function',
-    required: true,
-  },
   transformCode: {
     type: 'function',
   },
@@ -115,7 +111,6 @@ class Resolver {
       assetDependencies: ['react-native/Libraries/Image/AssetRegistry'],
     });
 
-    this._getModuleId = options.getModuleId;
     this._minifyCode = opts.minifyCode;
     this._polyfillModuleNames = opts.polyfillModuleNames || [];
 
@@ -137,7 +132,7 @@ class Resolver {
     return this._depGraph.getModuleForPath(entryFile);
   }
 
-  getDependencies(entryPath, options, transformOptions, onProgress) {
+  getDependencies(entryPath, options, transformOptions, onProgress, getModuleId) {
     const {platform, recursive} = getDependenciesValidateOpts(options);
     return this._depGraph.getDependencies({
       entryPath,
@@ -150,8 +145,7 @@ class Resolver {
         polyfill => resolutionResponse.prependDependency(polyfill)
       );
 
-      // currently used by HMR
-      resolutionResponse.getModuleId = this._getModuleId;
+      resolutionResponse.getModuleId = getModuleId;
       return resolutionResponse.finalize();
     });
   }
@@ -205,7 +199,7 @@ class Resolver {
     resolutionResponse.getResolvedDependencyPairs(module)
       .forEach(([depName, depModule]) => {
         if (depModule) {
-          resolvedDeps[depName] = this._getModuleId(depModule);
+          resolvedDeps[depName] = resolutionResponse.getModuleId(depModule);
         }
       });
 
@@ -251,7 +245,7 @@ class Resolver {
     if (module.isPolyfill()) {
       code = definePolyfillCode(code);
     } else {
-      const moduleId = this._getModuleId(module);
+      const moduleId = resolutionResponse.getModuleId(module);
       code = this.resolveRequires(
         resolutionResponse,
         module,
diff --git a/packager/react-packager/src/Server/__tests__/Server-test.js b/packager/react-packager/src/Server/__tests__/Server-test.js
index a7e702d398c..c96b9ce1dc4 100644
--- a/packager/react-packager/src/Server/__tests__/Server-test.js
+++ b/packager/react-packager/src/Server/__tests__/Server-test.js
@@ -22,14 +22,14 @@ jest.setMock('worker-farm', function() { return () => {}; })
 
 const Promise = require('promise');
 
-var Bundler = require('../../Bundler');
-var Server = require('../');
-var AssetServer = require('../../AssetServer');
+const Bundler = require('../../Bundler');
+const Server = require('../');
+const AssetServer = require('../../AssetServer');
 
-var FileWatcher;
+let FileWatcher;
 
 describe('processRequest', () => {
-  var server;
+  let server;
 
   const options = {
      projectRoots: ['root'],
@@ -56,8 +56,8 @@ describe('processRequest', () => {
 
   const invalidatorFunc = jest.fn();
   const watcherFunc = jest.fn();
-  var requestHandler;
-  var triggerFileChange;
+  let requestHandler;
+  let triggerFileChange;
 
   beforeEach(() => {
     FileWatcher = require('node-haste').FileWatcher;
@@ -135,7 +135,7 @@ describe('processRequest', () => {
       requestHandler,
       'index.ios.includeRequire.bundle'
     ).then(response => {
-      expect(response.body).toEqual('this is the source');
+      expect(response.body).toEqual('this is the source')
       expect(Bundler.prototype.bundle).toBeCalledWith({
         entryFile: 'index.ios.js',
         inlineSourceMap: false,
@@ -148,6 +148,7 @@ describe('processRequest', () => {
         runBeforeMainModule: ['InitializeJavaScriptAppEngine'],
         unbundle: false,
         entryModuleOnly: false,
+        isolateModuleIDs: false,
       });
     });
   });
@@ -170,6 +171,7 @@ describe('processRequest', () => {
         runBeforeMainModule: ['InitializeJavaScriptAppEngine'],
         unbundle: false,
         entryModuleOnly: false,
+        isolateModuleIDs: false,
       });
     });
   });
@@ -291,9 +293,9 @@ describe('processRequest', () => {
   });
 
   describe('/onchange endpoint', () => {
-    var EventEmitter;
-    var req;
-    var res;
+    let EventEmitter;
+    let req;
+    let res;
 
     beforeEach(() => {
       EventEmitter = require.requireActual('events').EventEmitter;
@@ -363,6 +365,7 @@ describe('processRequest', () => {
           runBeforeMainModule: ['InitializeJavaScriptAppEngine'],
           unbundle: false,
           entryModuleOnly: false,
+          isolateModuleIDs: false,
         })
       );
     });
@@ -384,6 +387,7 @@ describe('processRequest', () => {
             runBeforeMainModule: ['InitializeJavaScriptAppEngine'],
             unbundle: false,
             entryModuleOnly: false,
+            isolateModuleIDs: false,
           })
         );
     });
diff --git a/packager/react-packager/src/Server/index.js b/packager/react-packager/src/Server/index.js
index 608919b72c4..ecce02fde55 100644
--- a/packager/react-packager/src/Server/index.js
+++ b/packager/react-packager/src/Server/index.js
@@ -131,6 +131,10 @@ const bundleOpts = declareOpts({
     type: 'boolean',
     default: false,
   },
+  isolateModuleIDs: {
+    type: 'boolean',
+    default: false
+  }
 });
 
 const dependencyOpts = declareOpts({
@@ -167,7 +171,7 @@ class Server {
 
     const assetGlobs = opts.assetExts.map(ext => '**/*.' + ext);
 
-    var watchRootConfigs = opts.projectRoots.map(dir => {
+    let watchRootConfigs = opts.projectRoots.map(dir => {
       return {
         dir: dir,
         globs: [
@@ -338,7 +342,7 @@ class Server {
   }
 
   _processDebugRequest(reqUrl, res) {
-    var ret = '<!doctype html>';
+    let ret = '<!doctype html>';
     const pathname = url.parse(reqUrl).pathname;
     const parts = pathname.split('/').filter(Boolean);
     if (parts.length === 1) {
@@ -406,9 +410,9 @@ class Server {
 
   processRequest(req, res, next) {
     const urlObj = url.parse(req.url, true);
-    var pathname = urlObj.pathname;
+    const pathname = urlObj.pathname;
 
-    var requestType;
+    let requestType;
     if (pathname.match(/\.bundle$/)) {
       requestType = 'bundle';
     } else if (pathname.match(/\.map$/)) {
@@ -438,7 +442,7 @@ class Server {
     building.then(
       p => {
         if (requestType === 'bundle') {
-          var bundleSource = p.getSource({
+          const bundleSource = p.getSource({
             inlineSourceMap: options.inlineSourceMap,
             minify: options.minify,
             dev: options.dev,
@@ -453,7 +457,7 @@ class Server {
           }
           Activity.endEvent(startReqEventId);
         } else if (requestType === 'map') {
-          var sourceMap = p.getSourceMap({
+          let sourceMap = p.getSourceMap({
             minify: options.minify,
             dev: options.dev,
           });
@@ -466,7 +470,7 @@ class Server {
           res.end(sourceMap);
           Activity.endEvent(startReqEventId);
         } else if (requestType === 'assets') {
-          var assetsList = JSON.stringify(p.getAssets());
+          const assetsList = JSON.stringify(p.getAssets());
           res.setHeader('Content-Type', 'application/json');
           res.end(assetsList);
           Activity.endEvent(startReqEventId);