diff --git a/lib/polyfills.ts b/lib/polyfills.ts
index 4d15e1dc..4d2c5632 100644
--- a/lib/polyfills.ts
+++ b/lib/polyfills.ts
@@ -46,5 +46,7 @@ const ArrayConstructors = [
 ];
 
 ArrayConstructors.forEach((ArrayConstructor) => {
-  ArrayConstructor.prototype.at = ArrayConstructor.prototype.at ?? at;
+  if (!Object.prototype.hasOwnProperty.call(ArrayConstructor, 'at')) {
+    ArrayConstructor.prototype.at = at;
+  }
 });