diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..ed273cc
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,6 @@
+export default class AutoCheckElement extends HTMLElement {
+  readonly input: HTMLInputElement | null;
+  src: string;
+  csrf: string;
+  required: boolean;
+}
diff --git a/package.json b/package.json
index 0ac4990..d7f2071 100644
--- a/package.json
+++ b/package.json
@@ -4,10 +4,12 @@
   "description": "An input element that validates its value with a server endpoint.",
   "repository": "github/auto-check-element",
   "files": [
-    "dist"
+    "dist",
+    "index.d.ts"
   ],
   "main": "dist/index.umd.js",
   "module": "dist/index.esm.js",
+  "types": "index.d.ts",
   "scripts": {
     "clean": "rm -rf dist/",
     "lint": "github-lint",