diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..3a188b4
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,19 @@
+declare module "fpcalc" {
+    export interface FpcalcOptions {
+        length?: number
+        raw?: boolean
+        command?: string
+    }
+
+    export interface FpcalcResult<T extends Buffer | string> {
+        file?: string
+        duration?: number
+        fingerprint: T
+    }
+
+    function fpcalc(file: string | ReadableStream, callback: (err: Error, result: FpcalcResult<string>) => void)
+    function fpcalc(file: string | ReadableStream, options: FpcalcOptions & { raw: true }, callback: (err: Error, result: FpcalcResult<Buffer>) => void)
+    function fpcalc(file: string | ReadableStream, options: FpcalcOptions, callback: (err: Error, result: FpcalcResult<string>) => void)
+
+    export default fpcalc
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index 8c1ec16..a5a6058 100644
--- a/package.json
+++ b/package.json
@@ -31,5 +31,6 @@
   },
   "devDependencies": {
     "tape": "^4.2.1"
-  }
-}
+  },
+  "types": "index.d.ts"
+}
\ No newline at end of file