Pruning Weeping Mullbery trees

[Weeper]

I would like to know when is the best time to prune a weeping mullberry (mophead mullberry) back to the naked claw stage??

The picture shows a weeping mullberry pruned back to the 'naked claw' state.

 

[Stumper]

While the leaves are off. (dormant period)

 

[Weeper]

Thank you.

I was hoping that it would be now before all the leaves fall off.