diff --git a/types/gzip-size/index.d.ts b/types/gzip-size/index.d.ts
index 12b1899b54..cab8ec225b 100644
--- a/types/gzip-size/index.d.ts
+++ b/types/gzip-size/index.d.ts
@@ -1,13 +1,19 @@
-// Type definitions for gzip-size 3.0
+// Type definitions for gzip-size 4.0
 // Project: https://github.com/sindresorhus/gzip-size
 // Definitions by: York Yao <https://github.com/plantain-00>
+//                 Jimi van der Woning <https://github.com/jimivdw>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /// <reference types="node" />
 
-declare function gzipSize(input: string | Buffer, callback: (error: Error, size: number) => void): string;
-export = gzipSize;
+import * as stream from 'stream';
+import * as zlib from 'zlib';
+
+declare function gzipSize(input: string | Buffer, options?: zlib.ZlibOptions): Promise<number>;
+
 declare namespace gzipSize {
-    function sync(input: string | Buffer): number;
-    function stream(): NodeJS.ReadWriteStream;
+    function sync(input: string | Buffer, options?: zlib.ZlibOptions): number;
+    function stream(options?: zlib.ZlibOptions): stream.PassThrough;
 }
+
+export = gzipSize;
diff --git a/types/gzip-size/v3/gzip-size-tests.ts b/types/gzip-size/v3/gzip-size-tests.ts
new file mode 100644
index 0000000000..f07d99bd50
--- /dev/null
+++ b/types/gzip-size/v3/gzip-size-tests.ts
@@ -0,0 +1,7 @@
+import gzipSize = require('gzip-size');
+
+const string = 'Lorem ipsum dolor sit amet.';
+
+console.log(string.length);
+
+console.log(gzipSize.sync(string));
diff --git a/types/gzip-size/v3/index.d.ts b/types/gzip-size/v3/index.d.ts
new file mode 100644
index 0000000000..12b1899b54
--- /dev/null
+++ b/types/gzip-size/v3/index.d.ts
@@ -0,0 +1,13 @@
+// Type definitions for gzip-size 3.0
+// Project: https://github.com/sindresorhus/gzip-size
+// Definitions by: York Yao <https://github.com/plantain-00>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+/// <reference types="node" />
+
+declare function gzipSize(input: string | Buffer, callback: (error: Error, size: number) => void): string;
+export = gzipSize;
+declare namespace gzipSize {
+    function sync(input: string | Buffer): number;
+    function stream(): NodeJS.ReadWriteStream;
+}
diff --git a/types/gzip-size/v3/tsconfig.json b/types/gzip-size/v3/tsconfig.json
new file mode 100644
index 0000000000..88a695711b
--- /dev/null
+++ b/types/gzip-size/v3/tsconfig.json
@@ -0,0 +1,28 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../../",
+        "typeRoots": [
+            "../../"
+        ],
+        "types": [],
+        "paths": {
+            "gzip-size": [
+                "gzip-size/v3"
+            ]
+        },
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "gzip-size-tests.ts"
+    ]
+}
diff --git a/types/gzip-size/v3/tslint.json b/types/gzip-size/v3/tslint.json
new file mode 100644
index 0000000000..e60c15844f
--- /dev/null
+++ b/types/gzip-size/v3/tslint.json
@@ -0,0 +1,3 @@
+{
+    "extends": "dtslint/dt.json"
+}
\ No newline at end of file