diff --git a/js/js.libraries/src/core/collections/AbstractMutableList.kt b/js/js.libraries/src/core/collections/AbstractMutableList.kt
index 82520388df6..af34d7e9185 100644
--- a/js/js.libraries/src/core/collections/AbstractMutableList.kt
+++ b/js/js.libraries/src/core/collections/AbstractMutableList.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
+ * Copyright 2010-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -174,7 +174,7 @@ public abstract class AbstractMutableList<E> protected constructor() : AbstractM
         }
     }
 
-    private class SubList<E>(private val list: AbstractMutableList<E>, private val fromIndex: Int, toIndex: Int) : AbstractMutableList<E>() {
+    private class SubList<E>(private val list: AbstractMutableList<E>, private val fromIndex: Int, toIndex: Int) : AbstractMutableList<E>(), RandomAccess {
         private var _size: Int = 0
 
         init {
diff --git a/libraries/stdlib/src/kotlin/collections/AbstractList.kt b/libraries/stdlib/src/kotlin/collections/AbstractList.kt
index 71ff76c4ae4..b64f2d073d6 100644
--- a/libraries/stdlib/src/kotlin/collections/AbstractList.kt
+++ b/libraries/stdlib/src/kotlin/collections/AbstractList.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
+ * Copyright 2010-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,7 +44,7 @@ public abstract class AbstractList<out E> protected constructor() : AbstractColl
 
     override fun subList(fromIndex: Int, toIndex: Int): List<E> = SubList(this, fromIndex, toIndex)
 
-    internal open class SubList<out E>(private val list: AbstractList<E>, private val fromIndex: Int, toIndex: Int) : AbstractList<E>() {
+    private class SubList<out E>(private val list: AbstractList<E>, private val fromIndex: Int, toIndex: Int) : AbstractList<E>(), RandomAccess {
         private var _size: Int = 0
 
         init {