diff --git a/packages/core/package.json b/packages/core/package.json
index ba4224a00..00b375885 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -5,6 +5,7 @@
   "main": "build/index.js",
   "author": "Silverhand Inc. <contact@silverhand.io>",
   "license": "MPL-2.0",
+  "type": "module",
   "private": true,
   "scripts": {
     "preinstall": "npx only-allow pnpm",
diff --git a/packages/core/tsconfig.json b/packages/core/tsconfig.json
index 64517c9bb..7e9a613ab 100644
--- a/packages/core/tsconfig.json
+++ b/packages/core/tsconfig.json
@@ -5,10 +5,16 @@
       "node",
       "jest",
       "jest-matcher-specific-error"
-    ]
+    ],
+    "module": "ESNext"
   },
   "include": [
     "src",
     "jest.*.ts"
-  ]
+  ],
+  "ts-node": {
+    "moduleTypes": {
+      "jest.config.ts": "cjs"
+    }
+  }
 }
diff --git a/packages/jest-config/jest.config.ts b/packages/jest-config/jest.config.ts
index ab9532f89..c41ffa9e6 100644
--- a/packages/jest-config/jest.config.ts
+++ b/packages/jest-config/jest.config.ts
@@ -5,7 +5,7 @@ const baseConfig: Config.InitialOptions = Object.freeze({
   preset: 'ts-jest',
   transform: {
     // Enable JS/JSX transformation
-    '\\.(ts|js)x?$': 'ts-jest',
+    '\\.(ts)x?$': 'ts-jest',
     '\\.(svg)$': 'jest-transform-stub',
   },
   transformIgnorePatterns: [