diff --git a/jest.config.mjs b/jest.config.mjs
new file mode 100644
index 0000000..2e42917
--- /dev/null
+++ b/jest.config.mjs
@@ -0,0 +1,16 @@
+const ES_PACKAGES_TO_TRANSFORM = [];
+
+/** @type {import('jest').Config} */
+const config = {
+  collectCoverageFrom: ['src/**/*.ts', '!src/**/types.ts'],
+  reporters: ['default'],
+  transform: {
+    '^.+\\.(t|j)sx?$': '@swc/jest',
+  },
+  resolver: 'ts-jest-resolver',
+  transformIgnorePatterns: [
+    `node_modules/(?!(${ES_PACKAGES_TO_TRANSFORM.join('|')}))/node_modules/.+\\.js`,
+  ],
+};
+
+export default config;
diff --git a/package.json b/package.json
index e3ceeec..79895c8 100644
--- a/package.json
+++ b/package.json
@@ -18,19 +18,20 @@
     "email": "vlad@shelf.io",
     "url": "https://shelf.io"
   },
-  "main": "lib",
+  "sideEffects": false,
+  "type": "module",
+  "exports": "./lib/index.js",
+  "module": "./lib/index.js",
   "types": "lib/index.d.ts",
   "files": [
     "lib"
   ],
   "scripts": {
-    "benchmark": "babel benchmark.ts | node",
-    "build": "rm -rf lib/ && yarn build:types && babel src --out-dir lib --ignore '**/*.test.ts' --extensions '.ts'",
-    "build:types": "tsc --emitDeclarationOnly --declaration --isolatedModules false --declarationDir lib",
+    "benchmark": "tsx benchmark.ts",
+    "build": "rm -rf lib/ && tsc",
     "coverage": "jest --coverage",
     "lint": "yarn lint:ci --fix",
     "lint:ci": "eslint . --quiet",
-    "prepack": "yarn build",
     "test": "jest src",
     "type-check": "tsc --noEmit",
     "type-check:watch": "npm run type-check -- --watch"
@@ -43,22 +44,20 @@
       "eslint --fix"
     ]
   },
-  "babel": {
-    "extends": "@shelf/babel-config/backend"
-  },
-  "jest": {
-    "testEnvironment": "node"
+  "resolutions": {
+    "strip-ansi": "6.0.1",
+    "wrap-ansi": "7.0.0",
+    "string-width": "4.2.3"
   },
   "dependencies": {
     "runes": "0.4.3",
-    "string-length": "4.0.2"
+    "string-length": "6.0.0"
   },
   "devDependencies": {
-    "@babel/cli": "7.26.4",
-    "@babel/core": "7.26.0",
-    "@shelf/babel-config": "3.0.0",
     "@shelf/eslint-config": "4.4.0",
     "@shelf/tsconfig": "0.1.0",
+    "@swc/core": "1.10.7",
+    "@swc/jest": "0.2.37",
     "@types/benchmark": "2.1.5",
     "@types/jest": "29.5.14",
     "@types/node": "18",
@@ -70,6 +69,8 @@
     "jest": "29.7.0",
     "lint-staged": "15.3.0",
     "prettier": "3.4.2",
+    "ts-jest-resolver": "2.0.1",
+    "tsx": "4.19.2",
     "typescript": "5.7.3"
   },
   "engines": {
diff --git a/src/index.test.ts b/src/index.test.ts
index eeffcea..648d326 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -1,4 +1,4 @@
-import fastChunkString from './index';
+import fastChunkString from './index.js';
 
 const text = 'hello my dear world';
 
diff --git a/src/index.ts b/src/index.ts
index 6d18b01..3facc56 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,7 @@
 import runes from 'runes';
 import stringLength from 'string-length';
 
-export default function fastChunkString(
+function fastChunkString(
   str: string,
   {
     size,
@@ -49,4 +49,4 @@ function getChunksUnicode(str: string, size: number): string[] {
 
   return chunks;
 }
-module.exports = fastChunkString;
+export default fastChunkString;
diff --git a/tsconfig.json b/tsconfig.json
index 5bbaf96..e394b40 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,8 +1,15 @@
 {
   "extends": "@shelf/tsconfig/backend",
   "compilerOptions": {
-    "strict": true
+    "strict": true,
+    "module": "ESNext",
+    "target": "ESNext",
+    "moduleResolution": "bundler",
+    "declaration": true,
+    "resolveJsonModule": true,
+    "declarationMap": true,
+    "outDir": "lib"
   },
-  "exclude": ["node_modules"],
+  "exclude": ["node_modules", "**/*.test.*", "**/mocks.ts"],
   "include": ["src"]
 }