diff --git a/lib/dom.js b/lib/dom.js
index 1459059fb..40f60db82 100644
--- a/lib/dom.js
+++ b/lib/dom.js
@@ -62,7 +62,9 @@ function arrayIncludes (list) {
 
 function copy(src,dest){
 	for(var p in src){
-		dest[p] = src[p];
+		if (Object.prototype.hasOwnProperty.call(src, p)) {
+			dest[p] = src[p];
+		}
 	}
 }