diff --git a/dist/action.mjs b/dist/action.mjs
index 189557b..4f22d6e 100644
--- a/dist/action.mjs
+++ b/dist/action.mjs
@@ -1,8 +1,23 @@
-import fs from 'node:fs';
+import 'node:fs';
+import fsPromises from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
 import { execFileSync } from 'node:child_process';
 
+/**
+ * Retrieves the value of an environment variable.
+ *
+ * @param name - The name of the environment variable.
+ * @returns The value of the environment variable.
+ * @throws Error if the environment variable is not defined.
+ */
+function mustGetEnvironment(name) {
+    const value = process.env[name];
+    if (value === undefined) {
+        throw new Error(`the ${name} environment variable must be defined`);
+    }
+    return value;
+}
 /**
  * Retrieves the value of a GitHub Actions input.
  *
@@ -17,11 +32,14 @@ function getInput(name) {
  * Sets the value of a GitHub Actions output.
  *
  * @param name - The name of the GitHub Actions output.
- * @param value - The value of the GitHub Actions output
+ * @param value - The value to set for the GitHub Actions output.
+ * @returns A promise that resolves when the value is successfully set.
  */
-function setOutput(name, value) {
-    fs.appendFileSync(process.env["GITHUB_OUTPUT"], `${name}=${value}${os.EOL}`);
+async function setOutput(name, value) {
+    const filePath = mustGetEnvironment("GITHUB_OUTPUT");
+    await fsPromises.appendFile(filePath, `${name}=${value}${os.EOL}`);
 }
+
 /**
  * Logs an error message in GitHub Actions.
  *
@@ -109,7 +127,7 @@ function getContext() {
 try {
     const context = getContext();
     configureProject(context);
-    setOutput("build-dir", context.buildDir);
+    await setOutput("build-dir", context.buildDir);
     if (context.build.enabled) {
         buildProject(context);
     }
diff --git a/package.json b/package.json
index 97753e4..aec7fb8 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "test": "jest"
   },
   "dependencies": {
-    "gha-utils": "^0.2.0"
+    "gha-utils": "^0.3.0"
   },
   "devDependencies": {
     "@eslint/js": "^9.10.0",
diff --git a/src/action.ts b/src/action.ts
index 58b499a..cd1df4b 100644
--- a/src/action.ts
+++ b/src/action.ts
@@ -7,7 +7,7 @@ try {
 
   configureProject(context);
 
-  setOutput("build-dir", context.buildDir);
+  await setOutput("build-dir", context.buildDir);
 
   if (context.build.enabled) {
     buildProject(context);
diff --git a/yarn.lock b/yarn.lock
index 7cb2244..5eb2328 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2376,10 +2376,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"gha-utils@npm:^0.2.0":
-  version: 0.2.0
-  resolution: "gha-utils@npm:0.2.0"
-  checksum: 10c0/34e597b9011518c36abbb4bbbfb0ecaf16171e2bafad3a9ddbbdd3c3b2c1234eb8afc06fc84837565afca5e9ca9d48eb62a7238613ab808d8e1c7e0b6651e2c6
+"gha-utils@npm:^0.3.0":
+  version: 0.3.0
+  resolution: "gha-utils@npm:0.3.0"
+  checksum: 10c0/f8fe13abc48640d60072518260c8e6d5fb695e933c3ef2e16970838d3676254d21ed239e4267ae65f83dc5c167a1bd97959005b713217ead7bf8873e79b2343b
   languageName: node
   linkType: hard
 
@@ -4108,7 +4108,7 @@ __metadata:
     "@types/jest": "npm:^29.5.13"
     "@types/node": "npm:^22.5.5"
     eslint: "npm:^9.9.1"
-    gha-utils: "npm:^0.2.0"
+    gha-utils: "npm:^0.3.0"
     jest: "npm:^29.7.0"
     prettier: "npm:^3.3.3"
     rollup: "npm:^4.21.3"