diff --git a/test/parallel/test-npm-install.js b/test/parallel/test-npm-install.js
index b6ef67bf322ea3..c716e48aefedab 100644
--- a/test/parallel/test-npm-install.js
+++ b/test/parallel/test-npm-install.js
@@ -32,11 +32,12 @@ const pkgPath = path.join(common.tmpDir, 'package.json');
 
 fs.writeFileSync(pkgPath, pkgContent);
 
+const env = Object.create(process.env);
+env['PATH'] = path.dirname(process.execPath);
+
 const proc = spawn(process.execPath, args, {
   cwd: common.tmpDir,
-  env: {
-    PATH: path.dirname(process.execPath)
-  }
+  env: env
 });
 
 function handleExit(code, signalCode) {