diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..6bcc928
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,11 @@
+/**
+ * Returns the SHA-256 hash of `message` as an hexadecimal string.
+ * @param message The message to hash
+ */
+export function sha256(message: string | ArrayLike<number> | Uint8Array | ArrayBuffer): string;
+
+/**
+ * Returns the SHA-224 hash of `message` as an hexadecimal string.
+ * @param message The message to hash
+ */
+export function sha224(message: string | ArrayLike<number> | Uint8Array | ArrayBuffer): string;
diff --git a/package.json b/package.json
index b0b0df5..e657c7c 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "0.7.1",
   "description": "A simple SHA-256 / SHA-224 hash function for JavaScript supports UTF-8 encoding.",
   "main": "src/sha256.js",
+  "typings": "index.d.ts",
   "devDependencies": {
     "expect.js": "~0.3.1",
     "jscoverage": "~0.5.9",