diff --git a/bin/test-isolated b/bin/test-isolated
index c0057a9d5..1df1925a6 100755
--- a/bin/test-isolated
+++ b/bin/test-isolated
@@ -35,7 +35,7 @@ const run = path => {
     process.stderr.write(String(stderrBuffer));
   };
   return spawn('./bin/test', ['--require=sinon-bluebird', path], {
-    env: Object.assign({ FORCE_COLOR: '1' }, process.env),
+    env: { FORCE_COLOR: '1', PATH: process.env.PATH },
   }).then(onFinally, error => {
     ongoing.clear();
     onFinally(error);