--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/LengthNotWritableFilter.java	Fri Sep 01 14:13:42 2017 +0000
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/LengthNotWritableFilter.java	Sat Sep 02 14:26:29 2017 +0200
@@ -143,7 +143,7 @@
 
     @Override
     public ArrayData delete(final int index) {
-        extraElements.remove(index);
+        extraElements.remove(ArrayIndex.toLongIndex(index));
         underlying = underlying.delete(index);
         return this;
     }