diff --git a/build.config.js b/build.config.js
new file mode 100644
index 0000000..210e364
--- /dev/null
+++ b/build.config.js
@@ -0,0 +1,7 @@
+export default {
+  entries: ['./index.js'],
+  rollup: {
+    emitCJS: true,
+  },
+  failOnWarn: false,
+};
diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..ac8fb58
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,35 @@
+/// <reference types="node" />
+
+/**
+ * These definitions were written by BendingBender (https://github.com/BendingBender)
+ */
+
+export = crc32;
+
+declare function crc32(input: string | Buffer, partialCrc?: Buffer | number): Buffer;
+
+declare namespace crc32 {
+  /**
+   * Convenience method that returns a signed int instead of a `Buffer`.
+   *
+   * @example
+   * import crc32 = require('buffer-crc32');
+   *
+   * // works with buffers
+   * const buf = Buffer.from([0x00, 0x73, 0x75, 0x70, 0x20, 0x62, 0x72, 0x6f, 0x00]);
+   * crc32.signed(buf); // -> -1805997238
+   */
+  function signed(buffer: string | Buffer, partialCrc?: Buffer | number): number;
+
+  /**
+   * Convenience method that returns an unsigned int instead of a `Buffer`.
+   *
+   * @example
+   * import crc32 = require('buffer-crc32');
+   *
+   * // works with buffers
+   * const buf = Buffer.from([0x00, 0x73, 0x75, 0x70, 0x20, 0x62, 0x72, 0x6f, 0x00]);
+   * crc32.unsigned(buf); // -> 2488970058
+   */
+  function unsigned(buffer: string | Buffer, partialCrc?: Buffer | number): number;
+}
diff --git a/package.json b/package.json
index e9f5189..dc29702 100644
--- a/package.json
+++ b/package.json
@@ -20,12 +20,12 @@
     "type": "git",
     "url": "git://github.com/brianloveswords/buffer-crc32.git"
   },
-  "main": "index.js",
   "scripts": {
     "test": "tap tests/*.test.js --reporter classic",
+    "build": "npx unbuild@2.0.0 && npx cpy-cli index.d.ts dist --rename=index.d.cts && npx cpy-cli index.d.ts dist --rename=index.d.mts",
+    "prepublishOnly": "npm run build",
     "format": "prettier --write --log-level warn \"**/*.{json,md,js}\""
   },
-  "type": "commonjs",
   "dependencies": {},
   "devDependencies": {
     "prettier": "^3.2.4",
@@ -36,7 +36,19 @@
     "node": ">=8.0.0"
   },
   "license": "MIT",
+  "type": "commonjs",
+  "exports": {
+    ".": {
+      "import": "./dist/index.mjs",
+      "require": "./dist/index.cjs"
+    }
+  },
+  "main": "./dist/index.cjs",
+  "types": "./index.d.ts",
   "files": [
-    "index.js"
+    "dist",
+    "index.d.ts",
+    "LICENSE",
+    "README.md"
   ]
 }