diff --git a/nacl-util.d.ts b/nacl-util.d.ts
new file mode 100644
index 0000000..49fa190
--- /dev/null
+++ b/nacl-util.d.ts
@@ -0,0 +1,11 @@
+// Type definitions for tweetnacl-util
+
+declare var util: util;
+export = util;
+
+interface util {
+    decodeUTF8(s: string): Uint8Array;
+    encodeUTF8(arr: Uint8Array): string;
+    encodeBase64(arr: Uint8Array): string;
+    decodeBase64(s: string): Uint8Array;
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index 9abb64d..9d6ffa0 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "0.13.3",
   "description": "String encoding utilitlies extracted from TweetNaCl.js",
   "main": "nacl-util.js",
+  "types": "nacl-util.d.ts",
   "scripts": {
     "build": "uglifyjs nacl-util.js -c -m -o nacl-util.min.js"
   },