diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f4b790ef..6d3aaf46 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,6 @@ jobs:
           - '18'
           - '20'
           - '22'
-
     steps:
     - uses: actions/checkout@v4
     - name: Setup Node.js ${{ matrix.node-version }}
@@ -24,11 +23,9 @@ jobs:
       with:
         cache: npm
         node-version: ${{ matrix.node-version }}
-
     - run: npm install -g nyc
     - run: npm ci
     - run: npm run test:cover
-
     - uses: codecov/codecov-action@v5
       with:
         files: coverage/coverage-final.json
@@ -39,7 +36,6 @@ jobs:
     strategy:
       matrix:
         browser: [ChromeHeadless, FirefoxHeadless]
-
     steps:
     - uses: actions/checkout@v4
     - name: Setup Node.js
@@ -54,7 +50,6 @@ jobs:
 
   deno:
     runs-on: ubuntu-latest
-
     steps:
     - uses: actions/checkout@v4
     - name: Setup Deno
@@ -62,15 +57,14 @@ jobs:
       with:
         deno-version: "v2.x"
     - run: npm ci
-    - run: deno test test/deno_test.ts
+    - run: npm run test:deno
 
   bun:
     runs-on: ubuntu-latest
-
     steps:
     - uses: actions/checkout@v4
     - name: Setup Bun
       uses: oven-sh/setup-bun@v2
     - run: bun install
-    - run: bun test test/bun.spec.ts
+    - run: npm run test:bun
 
diff --git a/karma.conf.ts b/karma.conf.ts
index 8ee789f1..b4a51507 100644
--- a/karma.conf.ts
+++ b/karma.conf.ts
@@ -43,9 +43,8 @@ export default function configure(config: any) {
             test: /\.tsx?$/,
             loader: "ts-loader",
             options: {
-              configFile: "tsconfig.test-karma.json",
-              // FIXME: some types for dependencies cannot be resolved, so ignore type checking for now.
               transpileOnly: true,
+              configFile: "tsconfig.test-karma.json",
             },
           },
         ],
diff --git a/package.json b/package.json
index a2603f16..5d03ab56 100644
--- a/package.json
+++ b/package.json
@@ -4,21 +4,22 @@
   "description": "MessagePack for ECMA-262/JavaScript/TypeScript",
   "author": "The MessagePack community",
   "license": "ISC",
-  "main": "./dist/index.js",
+  "main": "./dist.cjs/index.js",
   "module": "./dist.esm/index.mjs",
   "cdn": "./dist.umd/msgpack.min.js",
   "unpkg": "./dist.umd/msgpack.min.js",
-  "types": "./dist/index.d.ts",
+  "types": "./dist.esm/index.d.ts",
   "sideEffects": false,
   "scripts": {
     "build": "npm publish --dry-run",
-    "prepare": "npm run clean && webpack --bail && tsc --build tsconfig.dist.json tsconfig.dist.esm.json && ts-node tools/esmify.ts dist.esm/*.js dist.esm/*/*.js",
+    "prepare": "npm run clean && webpack --bail && tsc --build tsconfig.dist.cjs.json tsconfig.dist.esm.json && ts-node tools/esmify.ts dist.esm/*.js dist.esm/*/*.js",
     "prepublishOnly": "npm run test:dist",
     "clean": "rimraf build dist dist.*",
     "test": "mocha 'test/**/*.test.ts'",
     "test:dist": "npm run lint && npm run test && npm run test:deno",
     "test:cover": "npm run cover:clean && npx nyc --no-clean npm run 'test' && npm run cover:report",
     "test:deno": "deno test test/deno_test.ts",
+    "test:bun": "bun test test/bun.spec.ts",
     "test:fuzz": "npm exec --yes -- jsfuzz@git+https://gitlab.com/gitlab-org/security-products/analyzers/fuzzers/jsfuzz.git#39e6cf16613a0e30c7a7953f62e64292dbd5d3f3 --fuzzTime 60 --no-versifier test/decode.jsfuzz.js corpus",
     "cover:clean": "rimraf .nyc_output coverage/",
     "cover:report": "npx nyc report --reporter=text-summary --reporter=html --reporter=json",
diff --git a/tsconfig.dist.json b/tsconfig.dist.cjs.json
similarity index 58%
rename from tsconfig.dist.json
rename to tsconfig.dist.cjs.json
index d78a9246..bb97412b 100644
--- a/tsconfig.dist.json
+++ b/tsconfig.dist.cjs.json
@@ -1,9 +1,11 @@
 {
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "outDir": "./dist",
-    "declaration": true,
+    "module": "CommonJS",
+    "outDir": "./dist.cjs",
+    "declaration": false,
     "noEmitOnError": true,
+    "noEmit": false,
     "incremental": false
   },
   "include": ["src/**/*.ts"]
diff --git a/tsconfig.dist.esm.json b/tsconfig.dist.esm.json
index 5ee9ac5e..42aeff69 100644
--- a/tsconfig.dist.esm.json
+++ b/tsconfig.dist.esm.json
@@ -1,10 +1,11 @@
 {
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "module": "es2020",
+    "module": "ES2020",
     "outDir": "./dist.esm",
-    "declaration": false,
+    "declaration": true,
     "noEmitOnError": true,
+    "noEmit": false,
     "incremental": false
   },
   "include": ["src/**/*.ts"]
diff --git a/tsconfig.dist.webpack.json b/tsconfig.dist.webpack.json
index edbaa9bd..687889a7 100644
--- a/tsconfig.dist.webpack.json
+++ b/tsconfig.dist.webpack.json
@@ -1,8 +1,9 @@
 {
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "module": "esnext",
+    "module": "ESNext",
     "noEmitOnError": true,
+    "noEmit": false,
     "outDir": "./build/webpack"
   },
   "include": ["src/**/*.ts"]
diff --git a/tsconfig.json b/tsconfig.json
index b97d9fec..60e468c6 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -3,7 +3,7 @@
     /* Basic Options */
     "target": "ES2020", /* the baseline */
     "module": "CommonJS",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
-    "lib": ["ES2024", "dom"],                             /* Specify library files to be included in the compilation. */
+    "lib": ["ES2024", "DOM"],                             /* Specify library files to be included in the compilation. */
     // "allowJs": true,                       /* Allow javascript files to be compiled. */
     // "checkJs": true,                       /* Report errors in .js files. */
     // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
@@ -41,6 +41,8 @@
     "noPropertyAccessFromIndexSignature": true,
     "noImplicitOverride": true,
     "verbatimModuleSyntax": false,
+    // "allowImportingTsExtensions": true,
+    "noEmit": true,
 
     /* Module Resolution Options */
     "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
@@ -55,6 +57,7 @@
     "esModuleInterop": true,                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
     // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
     "resolveJsonModule": true,
+    "skipLibCheck": true,
     "forceConsistentCasingInFileNames": true
 
     // "erasableSyntaxOnly": true
@@ -69,5 +72,5 @@
     // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
     // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
   },
-  "exclude": ["assembly"]
+  "exclude": ["example", "benchmark", "test/bun*", "test/deno*", "mod.ts"]
 }
diff --git a/tsconfig.test-karma.json b/tsconfig.test-karma.json
index 31174000..560ff840 100644
--- a/tsconfig.test-karma.json
+++ b/tsconfig.test-karma.json
@@ -1,8 +1,9 @@
 {
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "module": "esnext",
+    "module": "ESNext",
     "outDir": "./build/karma",
+    "noEmit": false,
     "incremental": false
   }
 }
diff --git a/webpack.config.mjs b/webpack.config.mjs
index 1eeb233f..3c15a82b 100644
--- a/webpack.config.mjs
+++ b/webpack.config.mjs
@@ -26,6 +26,7 @@ const config = {
         test: /\.tsx?$/,
         loader: "ts-loader",
         options: {
+          transpileOnly: true,
           configFile: "tsconfig.dist.webpack.json",
         },
       },