diff --git a/packages/npm-packages/ruby-wasm-wasi/package.json b/packages/npm-packages/ruby-wasm-wasi/package.json
index 48f507081..5a28b74cc 100644
--- a/packages/npm-packages/ruby-wasm-wasi/package.json
+++ b/packages/npm-packages/ruby-wasm-wasi/package.json
@@ -49,7 +49,7 @@
     "format": "prettier --write .",
     "build:static": "./tools/pack-bindgen-src.rb ./dist",
     "build:rollup": "rollup -c rollup.config.mjs",
-    "build:tsc": "tsc -p tsconfig.json && tsc -p tsconfig.cjs.json",
+    "build:tsc": "tsc -p tsconfig.esm.json && tsc -p tsconfig.cjs.json",
     "build": "npm run build:rollup && npm run build:tsc && npm run build:static && ./tools/post-build.sh ./dist"
   },
   "devDependencies": {
diff --git a/packages/npm-packages/ruby-wasm-wasi/tsconfig.esm.json b/packages/npm-packages/ruby-wasm-wasi/tsconfig.esm.json
new file mode 100644
index 000000000..c571fac08
--- /dev/null
+++ b/packages/npm-packages/ruby-wasm-wasi/tsconfig.esm.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./dist/esm"
+  }
+}
diff --git a/packages/npm-packages/ruby-wasm-wasi/tsconfig.json b/packages/npm-packages/ruby-wasm-wasi/tsconfig.json
index f1ccbbf86..b9c3cedb6 100644
--- a/packages/npm-packages/ruby-wasm-wasi/tsconfig.json
+++ b/packages/npm-packages/ruby-wasm-wasi/tsconfig.json
@@ -4,7 +4,6 @@
     "importHelpers": true,
     "allowJs": true,
     "module": "ES2015",
-    "outDir": "./dist/esm",
     "target": "es2017",
     "esModuleInterop": true,
     "moduleResolution": "node",