jmap prints negative value of MaxNewSize for 64-bit VM

jmap prints negative value for MaxNewSize for 64-bit VM (all collectors) (here, VM is started without -XX:MaxNewSize=)

using thread-local object allocation.
Parallel GC with 2 thread(s)

Heap Configuration:
   MinHeapFreeRatio = 40
   MaxHeapFreeRatio = 70
   MaxHeapSize = 536870912 (512.0MB)
   NewSize = 2686976 (2.5625MB)
   MaxNewSize = -65536 (-0.0625MB)
...