diff --git a/package.json b/package.json
index c9a0f1e..31ab382 100644
--- a/package.json
+++ b/package.json
@@ -3,13 +3,14 @@
   "version": "1.1.0",
   "description": "TypeScript library for easy socket upgrades (STARTTLS).",
   "type": "module",
-  "main": "lib/index.js",
-  "types": "lib/index.d.ts",
-  "module": "lib/index.js",
+  "main": "./lib/cjs/index.js",
+  "module": "./lib/esm/index.js",
+  "types": "./lib/esm/index.d.ts",
   "exports": {
     ".": {
-      "import": "./lib/index.js",
-      "types": "./lib/index.d.ts"
+      "require": "./lib/cjs/index.js",
+      "import": "./lib/esm/index.js",
+      "types": "./lib/esm/index.d.ts"
     }
   },
   "keywords": [
@@ -23,7 +24,9 @@
   ],
   "scripts": {
     "prepare": "npm run build",
-    "build": "tsc",
+    "build": "npm run build:cjs && npm run build:esm",
+    "build:esm": "tsc --module esnext --outDir lib/esm && echo '{\"type\": \"module\"}' > lib/esm/package.json",
+    "build:cjs": "tsc --module commonjs --outDir lib/cjs && echo '{\"type\": \"commonjs\"}' > lib/cjs/package.json",
     "test": "vitest",
     "coverage": "vitest --coverage --run"
   },
diff --git a/tsconfig.json b/tsconfig.json
index d5f898c..5632cea 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,12 +1,14 @@
 {
   "compilerOptions": {
-    "target": "ESNext",
-    "module": "NodeNext",
+    "target": "ES2020",
+    "module": "CommonJS",
+    "moduleResolution": "node",
+    "esModuleInterop": false,
     "declaration": true,
     "outDir": "./lib",
-    "lib": ["ESNext"],
+    "lib": ["ES2020", "DOM"],
     "strict": true
   },
   "include": ["src"],
-  "exclude": ["node_modules", "**/__tests__/*", "src/run.ts"]
+  "exclude": ["node_modules", "**/__tests__/*"]
 }