scala-js
diff --git a/‎library/src/main/scala/scala/scalajs/runtime/package.scala
Lines changed: 8 additions & 3 deletions b/‎library/src/main/scala/scala/scalajs/runtime/package.scala
Lines changed: 8 additions & 3 deletions
@@ -6,9 +6,14 @@ package object runtime {
 
   @inline final def genTraversableOnce2jsArray[A](
       col: GenTraversableOnce[A]): js.Array[A] = {
-    val result = new js.Array[A]
-    col.foreach(x => result.push(x))
-    result
+    col match {
+      case col: js.ArrayOps[A]     => col.result()
+      case col: js.WrappedArray[A] => col.array
+      case _ =>
+        val result = new js.Array[A]
+        col.foreach(x => result.push(x))
+        result
+    }
   }
 
   /** Information about the environment Scala.js runs in. */