diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..e2c3deb
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,51 @@
+declare module 'zlib-sync' {
+    export interface InflateOptions {
+        chunkSize?: number;
+        to?: 'string';
+        windowBits?: number;
+    }
+
+    export class Inflate {
+        readonly windowBits: number;
+        readonly result: Buffer | string | null;
+        readonly msg: string | null;
+        readonly err: number;
+        readonly chunkSize: number;
+        public constructor(options?: InflateOptions);
+        public push(buffer: Buffer, flush?: boolean | number): void;
+    }
+
+    export const Z_NO_FLUSH: number;
+    export const Z_PARTIAL_FLUSH: number;
+    export const Z_SYNC_FLUSH: number;
+    export const Z_FULL_FLUSH: number;
+    export const Z_FINISH: number;
+    export const Z_BLOCK: number;
+    export const Z_TREES: number;
+    export const Z_OK: number;
+    export const Z_STREAM_END: number;
+    export const Z_NEED_DICT: number;
+    export const Z_ERRNO: number;
+    export const Z_STREAM_ERROR: number;
+    export const Z_DATA_ERROR: number;
+    export const Z_MEM_ERROR: number;
+    export const Z_BUF_ERROR: number;
+    export const Z_VERSION_ERROR: number;
+    export const Z_NO_COMPRESSION: number;
+    export const Z_BEST_SPEED: number;
+    export const Z_BEST_COMPRESSION: number;
+    export const Z_DEFAULT_COMPRESSION: number;
+    export const Z_FILTERED: number;
+    export const Z_HUFFMAN_ONLY: number;
+    export const Z_RLE: number;
+    export const Z_FIXED: number;
+    export const Z_DEFAULT_STRATEGY: number;
+    export const Z_BINARY: number;
+    export const Z_TEXT: number;
+    export const Z_ASCII: number;
+    export const Z_UNKNOWN: number;
+    export const Z_DEFLATED: number;
+    export const Z_NULL: number;
+
+    export const ZLIB_VERSION: string;
+}
diff --git a/package.json b/package.json
index d3f69bf..94144ae 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
     "version": "0.1.5",
     "description": "Synchronous zlib bindings for NodeJS",
     "main": "index.js",
+    "types": "index.d.ts",
     "scripts": {
         "lint": "eslint --fix test",
         "test": "mocha"
@@ -25,6 +26,7 @@
         "nan": "^2.14.0"
     },
     "devDependencies": {
+        "@types/node": "^12.11.7",
         "mocha": "^4.0.1"
     }
 }