diff --git a/package.json b/package.json
index 9201cb0..93c4e45 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     "lint:package": "pnpm publint --pack npm",
     "format": "pnpm oxfmt",
     "format:check": "pnpm oxfmt --check",
-    "build": "pnpm tsc",
+    "build": "pnpm tsc -p tsconfig.build.json",
     "postbuild": "rollup dist/src/index.js --file dist/src/index.cjs --format cjs && cp dist/src/index.d.ts dist/src/index.d.cts",
     "prepublishOnly": "pnpm build",
     "build-js-client": "pnpm tsc --declaration false --outDir js-dist"
diff --git a/tsconfig.build.json b/tsconfig.build.json
new file mode 100644
index 0000000..ca153b1
--- /dev/null
+++ b/tsconfig.build.json
@@ -0,0 +1,7 @@
+{
+  // Build config for the published package: excludes test files from dist/.
+  // `extends` REPLACES the base exclude array (it does not merge), so
+  // "node_modules" must be re-listed here alongside the test glob.
+  "extends": "./tsconfig.json",
+  "exclude": ["node_modules", "src/**/*.test.*"]
+}
diff --git a/tsconfig.json b/tsconfig.json
index 811dec5..a265378 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,5 +12,5 @@
     "typeRoots": ["node_modules/@types"]
   },
   "include": ["src"],
-  "exclude": ["node_modules", "src/**/*.test.*/*"]
+  "exclude": ["node_modules"]
 }