diff --git a/gulp-size/gulp-size-tests.ts b/gulp-size/gulp-size-tests.ts
new file mode 100644
index 0000000000..bfa2c6a04b
--- /dev/null
+++ b/gulp-size/gulp-size-tests.ts
@@ -0,0 +1,27 @@
+/// <reference path="gulp-size.d.ts" />
+/// <reference path="../gulp/gulp.d.ts" />
+/// <reference path="../gulp-debug/gulp-debug.d.ts" />
+
+import gulp = require('gulp');
+import size = require('gulp-size');
+import debug = require('gulp-debug');
+
+gulp.task('default', () =>
+    gulp.src('fixture.js')
+        .pipe(size())
+        .pipe(gulp.dest('dist'))
+);
+
+
+gulp.task('default', () => {
+    var s = size();
+
+    return gulp.src('fixture.js')
+        .pipe(s)
+        .pipe(gulp.dest('dist'))
+        .pipe(debug({title: 'Total size ' + s.prettySize}));
+});
+
+
+size();
+size({showFiles: true, gzip: true});
diff --git a/gulp-size/gulp-size.d.ts b/gulp-size/gulp-size.d.ts
new file mode 100644
index 0000000000..d25f6ed94b
--- /dev/null
+++ b/gulp-size/gulp-size.d.ts
@@ -0,0 +1,23 @@
+// Type definitions for gulp-size v1.2.3
+// Project: https://github.com/sindresorhus/gulp-size
+// Definitions by: Tanguy Krotoff <https://github.com/tkrotoff>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+/// <reference path="../node/node.d.ts" />
+
+declare module 'gulp-size' {
+    interface IOptions {
+        showFiles?: boolean;
+        gzip?: boolean;
+        title?: string;
+    }
+
+    interface ISizeStream extends NodeJS.ReadWriteStream {
+      size: number;
+      prettySize: string;
+    }
+
+    function size(options?: IOptions): ISizeStream;
+
+    export = size;
+}