diff --git a/build/lib/typings/vinyl.d.ts b/build/lib/typings/vinyl.d.ts
new file mode 100644
index 00000000000..a85632e172b
--- /dev/null
+++ b/build/lib/typings/vinyl.d.ts
@@ -0,0 +1,112 @@
+// Type definitions for vinyl 0.4.3
+// Project: https://github.com/wearefractal/vinyl
+// Definitions by: vvakame <https://github.com/vvakame/>, jedmao <https://github.com/jedmao>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare module "vinyl" {
+
+	import fs = require("fs");
+
+	/**
+	 * A virtual file format.
+	 */
+	class File {
+		constructor(options?: {
+			/**
+			* Default: process.cwd()
+			*/
+			cwd?: string;
+			/**
+			 * Used for relative pathing. Typically where a glob starts.
+			 */
+			base?: string;
+			/**
+			 * Full path to the file.
+			 */
+			path?: string;
+			/**
+			 * Path history. Has no effect if options.path is passed.
+			 */
+			history?: string[];
+			/**
+			 * The result of an fs.stat call. See fs.Stats for more information.
+			 */
+			stat?: fs.Stats;
+			/**
+			 * File contents.
+			 * Type: Buffer, Stream, or null
+			 */
+			contents?: Buffer | NodeJS.ReadWriteStream;
+		});
+
+		/**
+		 * Default: process.cwd()
+		 */
+		public cwd: string;
+		/**
+		 * Used for relative pathing. Typically where a glob starts.
+		 */
+		public base: string;
+		/**
+		 * Full path to the file.
+		 */
+		public path: string;
+		public stat: fs.Stats;
+		/**
+		 * Type: Buffer|Stream|null (Default: null)
+		 */
+		public contents: Buffer | NodeJS.ReadableStream;
+		/**
+		 * Returns path.relative for the file base and file path.
+		 * Example:
+		 *  var file = new File({
+		 *    cwd: "/",
+		 *    base: "/test/",
+		 *    path: "/test/file.js"
+		 *  });
+		 *  console.log(file.relative); // file.js
+		 */
+		public relative: string;
+
+		public isBuffer(): boolean;
+
+		public isStream(): boolean;
+
+		public isNull(): boolean;
+
+		public isDirectory(): boolean;
+
+		/**
+		 * Returns a new File object with all attributes cloned. Custom attributes are deep-cloned.
+		 */
+		public clone(opts?: { contents?: boolean }): File;
+
+		/**
+		 * If file.contents is a Buffer, it will write it to the stream.
+		 * If file.contents is a Stream, it will pipe it to the stream.
+		 * If file.contents is null, it will do nothing.
+		 */
+		public pipe<T extends NodeJS.ReadWriteStream>(
+			stream: T,
+			opts?: {
+				/**
+				 * If false, the destination stream will not be ended (same as node core).
+				 */
+				end?: boolean;
+			}): T;
+
+		/**
+		 * Returns a pretty String interpretation of the File. Useful for console.log.
+		 */
+		public inspect(): string;
+	}
+
+	/**
+	 * This is required as per:
+	 * https://github.com/Microsoft/TypeScript/issues/5073
+	 */
+	namespace File {}
+
+	export = File;
+
+}
\ No newline at end of file
diff --git a/build/npm/postinstall.js b/build/npm/postinstall.js
index 421f0e454fb..0c56fe95b44 100644
--- a/build/npm/postinstall.js
+++ b/build/npm/postinstall.js
@@ -35,4 +35,6 @@ const extensions = [
 	'gulp'
 ];
 
-extensions.forEach(extension => npmInstall(`extensions/${extension}`));
\ No newline at end of file
+extensions.forEach(extension => npmInstall(`extensions/${extension}`));
+
+npmInstall('build'); // typings used in the build folder
\ No newline at end of file
diff --git a/build/package.json b/build/package.json
new file mode 100644
index 00000000000..d2d38c788cf
--- /dev/null
+++ b/build/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "build",
+  "version": "1.0.0",
+  "author": "Microsoft Corporation",
+  "devDependencies": {
+    "@types/xml2js": "^0.0.33"
+  }
+}
diff --git a/package.json b/package.json
index fd917b149a1..879d947df5c 100644
--- a/package.json
+++ b/package.json
@@ -46,10 +46,7 @@
     "@types/mocha": "^2.2.39",
     "@types/semver": "^5.3.30",
     "@types/sinon": "^1.16.34",
-    "@types/through": "^0.0.28",
     "@types/winreg": "^1.2.30",
-    "@types/vinyl": "^2.0.0",
-    "@types/xml2js": "^0.0.33",
     "azure-storage": "^0.3.1",
     "clean-css": "3.4.6",
     "coveralls": "^2.11.11",