diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e43dd138..5d3cc8fe 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,13 +16,17 @@ jobs:
             - uses: actions/checkout@v4
             - uses: actions/setup-node@v3
               with:
-                  node-version: "22.0.0"
+                  node-version: "22.13.0"
                   cache: npm
             - name: Build and test coverage
               run: |
                   npm ci
                   npm install c8
                   npm run coverage
+            - name: Print report
+              run: |
+                  ls coverage
+                  cat coverage/lcov.info
             - name: Coveralls
               uses: coverallsapp/github-action@master
               with:
diff --git a/package.json b/package.json
index cd9e53c9..edc7aecd 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,7 @@
   },
   "type": "module",
   "bin": {
-    "bare": "dist/bin/cli.js"
+    "bare": "dist/bin/bare.js"
   },
   "exports": {
     "./package.json": "./package.json",
@@ -53,13 +53,14 @@
   ],
   "scripts": {
     "build": "sh ./scripts/build.sh",
+    "check": "tsc --build && biome ci --error-on-warnings .",
     "clean": "rm -rf dist coverage",
     "coverage": "c8 --reporter=lcovonly npm test",
     "format": "biome format --write .",
     "lint": "biome lint .",
     "prepare": "validate-commit-msg",
-    "prepublishOnly": "npm run clean && npm test",
-    "test": "sh ./scripts/test.sh",
+    "prepublishOnly": "npm run clean && npm run build && npm test",
+    "test": "node --test --experimental-strip-types && npm run check",
     "version": "sh ./scripts/version.sh"
   },
   "devDependencies": {
diff --git a/scripts/build.sh b/scripts/build.sh
index 1152abf1..f1c76524 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -5,16 +5,13 @@ set -eu
 # https://kangax.github.io/compat-table/es2016plus
 TARGET='node20.10.0'
 
-# build .d.ts
-tsc --build src/
+# build ESM and .d.ts
+npx tsc --build src/tsconfig.bin.json
 
 cp -f dist/index.d.ts dist/index.d.cts
 
-# build ESM
-esbuild 'src/**/*.ts' --target=$TARGET --outdir=dist --log-level=warning
-
 # build CommonJS (fallback)
 esbuild src/index.ts --bundle --target=$TARGET --platform=node > dist/index.cjs
 
 # build standalone cli program
-esbuild dist/bin/cli.js --bundle --target=$TARGET --minify --keep-names --platform=node > dist/bin/bare
+esbuild dist/bin/bare.js --bundle --target=$TARGET --minify --keep-names --platform=node > dist/bin/bare
diff --git a/scripts/generate-tests-corpus.js b/scripts/generate-tests-corpus.ts
similarity index 93%
rename from scripts/generate-tests-corpus.js
rename to scripts/generate-tests-corpus.ts
index 997fa3bc..b3b136a5 100644
--- a/scripts/generate-tests-corpus.js
+++ b/scripts/generate-tests-corpus.ts
@@ -2,7 +2,7 @@
 
 import * as fs from "node:fs"
 import * as path from "node:path"
-import { Config, configure, parse, transform } from "@bare-ts/tools"
+import { Config, configure, parse, transform } from "../src/index.ts"
 
 const CORPUS_DIR = "./tests-corpus"
 
@@ -39,8 +39,7 @@ for (let category of fs.readdirSync(CORPUS_DIR)) {
                 completedConfig,
             )
             fs.writeFileSync(astPath, JSON.stringify(ast, null, 2))
-            let out
-            out = transform(content, { ...config, schema, generator: "ts" })
+            let out = transform(content, { ...config, schema, generator: "ts" })
             fs.writeFileSync(tsPath, out)
             out = transform(content, { ...config, schema, generator: "js" })
             fs.writeFileSync(jsPath, out)
diff --git a/scripts/test.sh b/scripts/test.sh
deleted file mode 100644
index 8e6fd98a..00000000
--- a/scripts/test.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/sh
-
-. scripts/build.sh
-
-# unit tests
-node --test
-
-# lint
-biome ci --error-on-warnings .
-
-# type check
-tsc --build src/ src/tsconfig-test.json tests-corpus/
diff --git a/src/ast/bare-configure.ts b/src/ast/bare-configure.ts
index d0e06f21..27e81a79 100644
--- a/src/ast/bare-configure.ts
+++ b/src/ast/bare-configure.ts
@@ -1,8 +1,8 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import type { Config } from "../core/config.js"
-import * as ast from "./bare-ast.js"
+import type { Config } from "../core/config.ts"
+import * as ast from "./bare-ast.ts"
 
 export function configure(schema: ast.Ast, config: Config): ast.Ast {
     const c: Configurator = {
diff --git a/src/ast/bare-normalization.ts b/src/ast/bare-normalization.ts
index 873acae6..a56a2886 100644
--- a/src/ast/bare-normalization.ts
+++ b/src/ast/bare-normalization.ts
@@ -1,7 +1,7 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import * as ast from "./bare-ast.js"
+import * as ast from "./bare-ast.ts"
 
 export function normalize(schema: ast.Ast): ast.Ast {
     const n: Context = { defs: [], dedup: new Map(), aliasCount: 0 }
diff --git a/src/ast/bare-semantic-checker.ts b/src/ast/bare-semantic-checker.ts
index 48ade740..a7cef458 100644
--- a/src/ast/bare-semantic-checker.ts
+++ b/src/ast/bare-semantic-checker.ts
@@ -1,14 +1,14 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import { CompilerError } from "../core/compiler-error.js"
-import type { Config } from "../core/config.js"
+import { CompilerError } from "../core/compiler-error.ts"
+import type { Config } from "../core/config.ts"
 import {
     CAMEL_CASE_RE,
     CONSTANT_CASE_RE,
     PASCAL_CASE_RE,
-} from "../utils/formatting.js"
-import * as ast from "./bare-ast.js"
+} from "../utils/formatting.ts"
+import * as ast from "./bare-ast.ts"
 
 export function checkSemantic(schema: ast.Ast, config: Config): ast.Ast {
     if (schema.defs.length === 0) {
diff --git a/src/bin/cli.ts b/src/bin/bare.ts
similarity index 99%
rename from src/bin/cli.ts
rename to src/bin/bare.ts
index 28112eb7..b66cd31d 100644
--- a/src/bin/cli.ts
+++ b/src/bin/bare.ts
@@ -7,7 +7,7 @@ import * as fs from "node:fs"
 import * as process from "node:process"
 import * as util from "node:util"
 import packageVersion from "../../VERSION.json" with { type: "json" }
-import { CompilerError, Config, transform } from "../index.js"
+import { CompilerError, Config, transform } from "../index.ts"
 
 const HELP_TEXT = `
 Usage: bare [options] [schema]
diff --git a/src/generator/bare-ast-utils.ts b/src/generator/bare-ast-utils.ts
index 23196f63..c5e88f2e 100644
--- a/src/generator/bare-ast-utils.ts
+++ b/src/generator/bare-ast-utils.ts
@@ -1,8 +1,8 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import * as ast from "../ast/bare-ast.js"
-import { CompilerError } from "../core/compiler-error.js"
+import * as ast from "../ast/bare-ast.ts"
+import { CompilerError } from "../core/compiler-error.ts"
 
 // This file is separated from ast folder because these utils are used for
 // facilitating code generation.
diff --git a/src/generator/bare-generator.ts b/src/generator/bare-generator.ts
index 12001f86..cad32459 100644
--- a/src/generator/bare-generator.ts
+++ b/src/generator/bare-generator.ts
@@ -1,8 +1,8 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import type * as ast from "../ast/bare-ast.js"
-import { dent, toConstantCase } from "../utils/formatting.js"
+import type * as ast from "../ast/bare-ast.ts"
+import { dent, toConstantCase } from "../utils/formatting.ts"
 
 export function generateBare(schema: ast.Ast): string {
     let result = ""
diff --git a/src/generator/js-generator.ts b/src/generator/js-generator.ts
index 8aa12b9a..5a1e8dd8 100644
--- a/src/generator/js-generator.ts
+++ b/src/generator/js-generator.ts
@@ -1,16 +1,16 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import * as ast from "../ast/bare-ast.js"
-import type { Config } from "../core/config.js"
+import * as ast from "../ast/bare-ast.ts"
+import type { Config } from "../core/config.ts"
 import {
     capitalize,
     dent,
     jsDoc,
     jsRpr,
     softSpace,
-} from "../utils/formatting.js"
-import * as utils from "./bare-ast-utils.js"
+} from "../utils/formatting.ts"
+import * as utils from "./bare-ast-utils.ts"
 
 export function generate(schema: ast.Ast, config: Config): string {
     const g: Gen = { config, symbols: ast.symbols(schema) }
diff --git a/src/index.ts b/src/index.ts
index ca5a713d..e0a44702 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,21 +1,21 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import { configure } from "./ast/bare-configure.js"
-import { normalize } from "./ast/bare-normalization.js"
-import { checkSemantic } from "./ast/bare-semantic-checker.js"
-import { Config } from "./core/config.js"
-import { generateBare } from "./generator/bare-generator.js"
-import { generate } from "./generator/js-generator.js"
-import { parse } from "./parser/bare-parser.js"
+import { configure } from "./ast/bare-configure.ts"
+import { normalize } from "./ast/bare-normalization.ts"
+import { checkSemantic } from "./ast/bare-semantic-checker.ts"
+import { Config } from "./core/config.ts"
+import { generateBare } from "./generator/bare-generator.ts"
+import { generate } from "./generator/js-generator.ts"
+import { parse } from "./parser/bare-parser.ts"
 
-export * from "./ast/bare-ast.js"
-export * from "./ast/bare-configure.js"
-export * from "./ast/bare-normalization.js"
-export * from "./core/compiler-error.js"
-export * from "./core/config.js"
-export * from "./generator/js-generator.js"
-export * from "./parser/bare-parser.js"
+export * from "./ast/bare-ast.ts"
+export * from "./ast/bare-configure.ts"
+export * from "./ast/bare-normalization.ts"
+export * from "./core/compiler-error.ts"
+export * from "./core/config.ts"
+export * from "./generator/js-generator.ts"
+export * from "./parser/bare-parser.ts"
 
 /**
  * Turn the schema `content` into a target language, taking `conf` into account.
diff --git a/src/parser/bare-lexer.test.ts b/src/parser/bare-lexer.test.ts
index e45f73e3..24539c11 100644
--- a/src/parser/bare-lexer.test.ts
+++ b/src/parser/bare-lexer.test.ts
@@ -3,7 +3,7 @@
 
 import * as assert from "node:assert/strict"
 import { test } from "node:test"
-import * as lex from "./bare-lexer.js"
+import * as lex from "./bare-lexer.ts"
 
 const SAMPLE = `
     const C = { # struct
diff --git a/src/parser/bare-lexer.ts b/src/parser/bare-lexer.ts
index 3d06bd69..0064dbbf 100644
--- a/src/parser/bare-lexer.ts
+++ b/src/parser/bare-lexer.ts
@@ -1,7 +1,7 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import { CompilerError } from "../core/compiler-error.js"
+import { CompilerError } from "../core/compiler-error.ts"
 
 const WHITE_SPACE_PATTERN = /\s/
 const PUNCTUATION_PATTERN = /[{}[\]()<>=|:,;.!?~+\\/$@#-]/
diff --git a/src/parser/bare-parser.ts b/src/parser/bare-parser.ts
index 88b79a69..353c9485 100644
--- a/src/parser/bare-parser.ts
+++ b/src/parser/bare-parser.ts
@@ -1,15 +1,15 @@
 //! Copyright (c) 2022 Victorien Elvinger
 //! Licensed under the MIT License (https://mit-license.org/)
 
-import * as ast from "../ast/bare-ast.js"
-import { CompilerError } from "../core/compiler-error.js"
-import type { Config } from "../core/config.js"
+import * as ast from "../ast/bare-ast.ts"
+import { CompilerError } from "../core/compiler-error.ts"
+import type { Config } from "../core/config.ts"
 import {
     ALL_CASE_RE,
     CONSTANT_CASE_RE,
     toPascalCase,
-} from "../utils/formatting.js"
-import * as lexer from "./bare-lexer.js"
+} from "../utils/formatting.ts"
+import * as lexer from "./bare-lexer.ts"
 
 export function parse(content: string, config: Config): ast.Ast {
     const p: Parser = { config, lex: lexer.create(content) }
diff --git a/src/tsconfig-test.json b/src/tsconfig-test.json
deleted file mode 100644
index 64145759..00000000
--- a/src/tsconfig-test.json
+++ /dev/null
@@ -1,18 +0,0 @@
-{
-  "extends": "../tsconfig-base.json",
-  "compilerOptions": {
-    "types": [
-      "node"
-    ],
-    "outDir": "../dist"
-  },
-  "include": [
-    "./bin/cli.ts",
-    "./**/*.test.ts"
-  ],
-  "references": [
-    {
-      "path": "."
-    }
-  ]
-}
diff --git a/src/tsconfig.bin.json b/src/tsconfig.bin.json
new file mode 100644
index 00000000..e4d04e09
--- /dev/null
+++ b/src/tsconfig.bin.json
@@ -0,0 +1,17 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "noEmit": false,
+    "rewriteRelativeImportExtensions": true,
+    "rootDir": ".",
+    "outDir": "../dist"
+  },
+  "include": [
+    "./bin/*.ts"
+  ],
+  "references": [
+    {
+      "path": "."
+    }
+  ]
+}
diff --git a/src/tsconfig.json b/src/tsconfig.json
index 1f7d3bdf..cf2641cb 100644
--- a/src/tsconfig.json
+++ b/src/tsconfig.json
@@ -1,15 +1,16 @@
 {
-  "extends": "../tsconfig-base.json",
+  "extends": "../tsconfig.json",
   "compilerOptions": {
     "composite": true,
-    "checkJs": false,
     "isolatedDeclarations": true,
-    "emitDeclarationOnly": true,
     "noEmit": false,
+    "rewriteRelativeImportExtensions": true,
+    "types": [],
+    "rootDir": ".",
     "outDir": "../dist"
   },
   "exclude": [
-    "./bin/cli.ts",
+    "./bin/**",
     "./**/*.test.ts"
   ]
 }
diff --git a/tests-corpus/index.test.js b/tests-corpus/index.test.ts
similarity index 99%
rename from tests-corpus/index.test.js
rename to tests-corpus/index.test.ts
index 67ce0c6f..e783d5c7 100644
--- a/tests-corpus/index.test.js
+++ b/tests-corpus/index.test.ts
@@ -11,7 +11,7 @@ import {
     configure,
     parse,
     transform,
-} from "@bare-ts/tools"
+} from "../src/index.ts"
 
 const CORPUS_DIR = "./tests-corpus"
 const INVALID_BARE_DIR = `${CORPUS_DIR}/invalid-bare-schema`
diff --git a/tests-corpus/tsconfig.json b/tests-corpus/tsconfig.json
deleted file mode 100644
index 85b4dede..00000000
--- a/tests-corpus/tsconfig.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "extends": "../tsconfig-base.json",
-  "compilerOptions": {
-    "types": ["node"]
-  }
-}
diff --git a/tsconfig-base.json b/tsconfig.json
similarity index 86%
rename from tsconfig-base.json
rename to tsconfig.json
index 00727ede..7474f25d 100644
--- a/tsconfig-base.json
+++ b/tsconfig.json
@@ -6,11 +6,13 @@
     ],
     "module": "NodeNext",
     "target": "ES2022",
+    "types": [
+      "node"
+    ],
 
     "noEmit": true,
 
-    "types": [],
-
+    "allowImportingTsExtensions": true,
     "esModuleInterop": true,
     "isolatedModules": true,
     "resolveJsonModule": true,
@@ -18,7 +20,6 @@
     "verbatimModuleSyntax": true,
 
     "allowUnreachableCode": false,
-    "checkJs": true,
     "noFallthroughCasesInSwitch": true,
     "noImplicitOverride": true,
     "noImplicitReturns": true,