diff --git a/package.json b/package.json
index 5344850..1c3127a 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,7 @@
     "type": "git",
     "url": "https://github.com/AVVS/hex-to-binary.git"
   },
+  "types": "./types/index.d.ts",
   "keywords": [
     "hex",
     "binary",
diff --git a/types/index.d.ts b/types/index.d.ts
new file mode 100644
index 0000000..d88fcd2
--- /dev/null
+++ b/types/index.d.ts
@@ -0,0 +1 @@
+export function hexToBinary(s: string): string
\ No newline at end of file