src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/JSObjectLinker.java

@@ -174,10 +174,12 @@
             return ((JSObject)jsobj).getSlot((Integer)key);
         } else if (key instanceof Number) {
             final int index = getIndex((Number)key);
             if (index > -1) {
                 return ((JSObject)jsobj).getSlot(index);
+            } else {
+                return ((JSObject)jsobj).getMember(JSType.toString(key));
             }
         } else if (isString(key)) {
             final String name = key.toString();
             // get with method name and signature. delegate it to beans linker!
             if (name.indexOf('(') != -1) {

@@ -191,11 +193,16 @@
     @SuppressWarnings("unused")
     private static void put(final Object jsobj, final Object key, final Object value) {
         if (key instanceof Integer) {
             ((JSObject)jsobj).setSlot((Integer)key, value);
         } else if (key instanceof Number) {
-            ((JSObject)jsobj).setSlot(getIndex((Number)key), value);
+            final int index = getIndex((Number)key);
+            if (index > -1) {
+                ((JSObject)jsobj).setSlot(index, value);
+            } else {
+                ((JSObject)jsobj).setMember(JSType.toString(key), value);
+            }
         } else if (isString(key)) {
             ((JSObject)jsobj).setMember(key.toString(), value);
         }
     }