diff --git a/lib/internal/test_runner/test.js b/lib/internal/test_runner/test.js
index e2d068e87bb051..3ebb4bc0a2dff9 100644
--- a/lib/internal/test_runner/test.js
+++ b/lib/internal/test_runner/test.js
@@ -240,7 +240,7 @@ class Test extends AsyncResource {
   }
 
   addPendingSubtest(deferred) {
-    this.pendingSubtests.push(deferred);
+    ArrayPrototypePush(this.pendingSubtests, deferred);
   }
 
   async processPendingSubtests() {