diff --git a/tools/broccoli/broccoli-typescript.ts b/tools/broccoli/broccoli-typescript.ts
index b4581b3029..beb0f58a47 100644
--- a/tools/broccoli/broccoli-typescript.ts
+++ b/tools/broccoli/broccoli-typescript.ts
@@ -41,6 +41,7 @@ class DiffingTSCompiler implements DiffingBroccoliPlugin {
     this.tsOpts = Object.create(options);
     this.tsOpts.outDir = this.cachePath;
     this.tsOpts.target = (<any>ts).ScriptTarget[options.target];
+    this.tsOpts.module = (<any>ts).ModuleKind[options.module];
     this.tsOpts.experimentalDecorators = true;
     this.rootFilePaths = options.rootFilePaths ? options.rootFilePaths.splice(0) : [];
     this.tsServiceHost = new CustomLanguageServiceHost(this.tsOpts, this.rootFilePaths,
diff --git a/tools/broccoli/trees/browser_tree.ts b/tools/broccoli/trees/browser_tree.ts
index ecb3214948..93653fd77b 100644
--- a/tools/broccoli/trees/browser_tree.ts
+++ b/tools/broccoli/trees/browser_tree.ts
@@ -83,6 +83,15 @@ module.exports = function makeBrowserTree(options, destinationPath) {
     ],
     destDir: '/'
   });
+  
+  var es5ModulesTree = new Funnel('modules', {
+    include: ['**/**'],
+    exclude: [
+      '**/*.cjs',
+      'benchmarks/e2e_test/**'
+    ],
+    destDir: '/'
+  });
 
   var scriptPathPatternReplacement = {
     match: '@@FILENAME_NO_EXT',
@@ -108,12 +117,20 @@ module.exports = function makeBrowserTree(options, destinationPath) {
     sourceRoot: '.',
     target: 'ES6'
   });
-
-  // Call Traceur to lower the ES6 build tree to ES5
-  var es5Tree = transpileWithTraceur(es6Tree, {
-    destExtension: '.js',
-    destSourceMapExtension: '.js.map',
-    traceurOptions: {modules: 'instantiate', sourceMaps: true}
+  
+  // Use TypeScript to transpile the *.ts files to ES5
+  var es5Tree = compileWithTypescript(es5ModulesTree, {
+    allowNonTsExtensions: false,
+    declaration: false,
+    emitDecoratorMetadata: true,
+    experimentalDecorators: true,
+    mapRoot: '',  // force sourcemaps to use relative path
+    module: 'System',
+    noEmitOnError: false,
+    rootDir: '.',
+    sourceMap: true,
+    sourceRoot: '.',
+    target: 'ES5'
   });
 
   // Now we add a few more files to the es6 tree that Traceur should not see
diff --git a/tools/broccoli/trees/node_tree.ts b/tools/broccoli/trees/node_tree.ts
index 6696a75ec8..7945357262 100644
--- a/tools/broccoli/trees/node_tree.ts
+++ b/tools/broccoli/trees/node_tree.ts
@@ -34,7 +34,7 @@ module.exports = function makeNodeTree(destinationPath) {
     experimentalDecorators: true,
     declaration: false,
     mapRoot: '', /* force sourcemaps to use relative path */
-    module: 'commonjs',
+    module: 'CommonJS',
     noEmitOnError: true,
     rootDir: '.',
     rootFilePaths: ['angular2/traceur-runtime.d.ts', 'angular2/globals.d.ts'],