diff --git a/Promise.js b/Promise.js
index f6206fa..2b684e9 100644
--- a/Promise.js
+++ b/Promise.js
@@ -256,7 +256,7 @@ object.Constructor('IterablePromise', Promise, {
 				[cur, ...other]
 			: other instanceof Promise ?
 				[...cur, other]
-			: cur.concat(other),
+			: [...cur, ...other],
 			'raw') },
 	push: function(elem){
 		return this.concat([elem]) },