diff --git a/types/gulp-size/gulp-size-tests.ts b/types/gulp-size/gulp-size-tests.ts
index 9aea965329..4a325abe27 100644
--- a/types/gulp-size/gulp-size-tests.ts
+++ b/types/gulp-size/gulp-size-tests.ts
@@ -1,6 +1,3 @@
-
-
-
 import * as gulp from 'gulp';
 import * as size from 'gulp-size';
 import * as debug from 'gulp-debug';
@@ -11,9 +8,8 @@ gulp.task('default', () =>
         .pipe(gulp.dest('dist'))
 );
 
-
 gulp.task('default', () => {
-    var s = size();
+    let s = size();
 
     return gulp.src('fixture.js')
         .pipe(s)
@@ -21,6 +17,5 @@ gulp.task('default', () => {
         .pipe(debug({title: 'Total size ' + s.prettySize}));
 });
 
-
 size();
 size({showFiles: true, gzip: true});
diff --git a/types/gulp-size/index.d.ts b/types/gulp-size/index.d.ts
index 374c58565e..088b916984 100644
--- a/types/gulp-size/index.d.ts
+++ b/types/gulp-size/index.d.ts
@@ -1,16 +1,18 @@
-// Type definitions for gulp-size v1.2.3
+// Type definitions for gulp-size 2.1
 // Project: https://github.com/sindresorhus/gulp-size
 // Definitions by: Tanguy Krotoff <https://github.com/tkrotoff>
+//                 Remisery <https://github.com/remisery>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /// <reference types="node" />
 
-
 declare namespace size {
     interface Options {
         showFiles?: boolean;
         gzip?: boolean;
         title?: string;
+        pretty?: boolean;
+        showTotal?: boolean;
     }
 
     interface SizeStream extends NodeJS.ReadWriteStream {
diff --git a/types/gulp-size/tsconfig.json b/types/gulp-size/tsconfig.json
index fe93b09ba6..0e924d2b94 100644
--- a/types/gulp-size/tsconfig.json
+++ b/types/gulp-size/tsconfig.json
@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"
@@ -22,4 +22,4 @@
         "index.d.ts",
         "gulp-size-tests.ts"
     ]
-}
\ No newline at end of file
+}
diff --git a/types/gulp-size/tslint.json b/types/gulp-size/tslint.json
new file mode 100644
index 0000000000..f93cf8562a
--- /dev/null
+++ b/types/gulp-size/tslint.json
@@ -0,0 +1,3 @@
+{
+    "extends": "dtslint/dt.json"
+}