diff --git a/lib/index.js b/lib/index.js
index dd0144b..3a6f442 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -69,7 +69,7 @@ function _delete(obj, prop) {
 		let clone, head = prop[i];
 
 		if (obj === null || typeof obj !== 'object' ||
-			!Array.isArray(obj) && obj[head] === undefined) {
+			!Array.isArray(obj) && !obj.hasOwnProperty(head)) {
 
 			return obj;
 		}