diff --git a/tools/broccoli/trees/node_tree.ts b/tools/broccoli/trees/node_tree.ts
index 43fd3eff51..eb4d6b7cf7 100644
--- a/tools/broccoli/trees/node_tree.ts
+++ b/tools/broccoli/trees/node_tree.ts
@@ -186,10 +186,7 @@ module.exports = function makeNodeTree(projects: string[], destinationPath: stri
writeFile('angular2/typings/browser.d.ts',
'// Typings needed for compilation with --target=es5\n' +
'///\n' +
- '///\n' +
- '// Workaround for https://github.com/ReactiveX/RxJS/issues/1270\n' +
- '// to be removed when angular2 upgrades to rxjs beta.2\n' +
- 'declare type PromiseConstructor = typeof Promise;\n')
+ '///\n')
]);
var nodeTree =