diff --git a/modules/@angular/core/src/util/decorators.ts b/modules/@angular/core/src/util/decorators.ts
index d497f16d2f..5928fb321c 100644
--- a/modules/@angular/core/src/util/decorators.ts
+++ b/modules/@angular/core/src/util/decorators.ts
@@ -26,7 +26,7 @@ export interface ClassDefinition {
    * Other methods on the class. Note that values should have type 'Function' but TS requires
    * all properties to have a narrower type than the index signature.
    */
-  [x: string]: Type | Function | any[] | undefined;
+  [x: string]: Type | Function | any[];
 }
 
 /**
diff --git a/scripts/ci-lite/build.sh b/scripts/ci-lite/build.sh
index 0fb8e9271c..3a24d80eb4 100755
--- a/scripts/ci-lite/build.sh
+++ b/scripts/ci-lite/build.sh
@@ -9,6 +9,7 @@ cd `dirname $0`
 source ./env.sh
 cd ../..
 
+$(npm bin)/tsc -v
 $(npm bin)/tsc -p tools
 cp tools/@angular/tsc-wrapped/package.json dist/tools/@angular/tsc-wrapped
 node dist/tools/@angular/tsc-wrapped/src/main -p modules
diff --git a/scripts/ci-lite/test_e2e.sh b/scripts/ci-lite/test_e2e.sh
index 93c137af0f..e1f9d317f6 100755
--- a/scripts/ci-lite/test_e2e.sh
+++ b/scripts/ci-lite/test_e2e.sh
@@ -23,6 +23,7 @@ echo 'travis_fold:end:test.buildPackages'
 
 
 ./scripts/ci-lite/offline_compiler_test.sh
+./tools/typings-test/test.sh
 
 echo 'travis_fold:start:test.e2e.localChrome'
 cd dist/
diff --git a/tools/tsconfig.json b/tools/tsconfig.json
index 948841ae97..f8a392730a 100644
--- a/tools/tsconfig.json
+++ b/tools/tsconfig.json
@@ -17,6 +17,7 @@
     "target": "es5"
   },
   "exclude": [
-    "node_modules"
+    "node_modules",
+    "typings-test"
   ]
 }
diff --git a/tools/typings-test/include-all.ts b/tools/typings-test/include-all.ts
new file mode 100644
index 0000000000..dd205706eb
--- /dev/null
+++ b/tools/typings-test/include-all.ts
@@ -0,0 +1,37 @@
+import * as compiler from '@angular/compiler';
+import * as compiler_cli from '@angular/compiler-cli';
+import * as compilerTesting from '@angular/compiler/testing';
+import * as coreTesting from '@angular/core';
+import * as core from '@angular/core/testing';
+import * as httpTesting from '@angular/http';
+import * as http from '@angular/http/testing';
+import * as platformBrowserTesting from '@angular/platform-browser';
+import * as platformBrowserDynmic from '@angular/platform-browser-dynamic';
+import * as platformBrowser from '@angular/platform-browser/testing';
+import * as platfomrServerTesting from '@angular/platform-server';
+import * as platfomrServer from '@angular/platform-server/testing';
+import * as router from '@angular/router';
+import * as routerDeprecatedTesting from '@angular/router-deprecated';
+import * as routerDeprecated from '@angular/router-deprecated/testing';
+import * as routerTesting from '@angular/router/testing';
+import * as upgrade from '@angular/upgrade';
+
+export default {
+  compiler,
+  compilerTesting,
+  compiler_cli,
+  core,
+  coreTesting,
+  http,
+  httpTesting,
+  platformBrowser,
+  platformBrowserTesting,
+  platformBrowserDynmic,
+  platfomrServer,
+  platfomrServerTesting,
+  router,
+  routerTesting,
+  routerDeprecated,
+  routerDeprecatedTesting,
+  upgrade
+}
diff --git a/tools/typings-test/test.sh b/tools/typings-test/test.sh
new file mode 100755
index 0000000000..ef20426d38
--- /dev/null
+++ b/tools/typings-test/test.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -ex -o pipefail
+
+# These ones can be `npm link`ed for fast development
+LINKABLE_PKGS=(
+  $(pwd)/dist/packages-dist/{common,core,compiler,compiler-cli,http,router,router-deprecated,upgrade,platform-{browser,browser-dynamic,server}}
+)
+
+TMPDIR=${TMPDIR:-/tmp/angular-build/}
+readonly TMP=$TMPDIR/typings-test.$(date +%s)
+mkdir -p $TMP
+cp -R -v tools/typings-test/* $TMP
+
+# run in subshell to avoid polluting cwd
+(
+  cd $TMP
+  # create package.json so that npm install doesn't pollute any parent node_modules's directory
+  npm init --yes
+  npm install ${LINKABLE_PKGS[*]}
+  npm install @types/es6-promise @types/es6-collections @types/jasmine rxjs@5.0.0-beta.6
+  npm install typescript@1.8.10
+  $(npm bin)/tsc --version
+  $(npm bin)/tsc -p tsconfig.json
+)
diff --git a/tools/typings-test/tsconfig.json b/tools/typings-test/tsconfig.json
new file mode 100644
index 0000000000..5abcf721b8
--- /dev/null
+++ b/tools/typings-test/tsconfig.json
@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "emitDecoratorMetadata": true,
+    "experimentalDecorators": true,
+    "module": "commonjs",
+    "moduleResolution": "node",
+    "outDir": "../../dist/typing-test/",
+    "rootDir": ".",
+    "target": "es5"
+  },
+  "files": [
+    "include-all.ts",
+    "node_modules/@types/es6-promise/index.d.ts",
+    "node_modules/@types/es6-collections/index.d.ts",
+    "node_modules/@types/jasmine/index.d.ts"
+  ]
+}