Will H1b existing validity change based on H1B amendment??

Hi,

I got 3 years H1b validity for the employer location. Now, I have to move for different project for an other Client.
For employer location to client location change, I have been asked for filing H1B amendment.

My new PRD and SOW remains only for 12 months.

Now my question is, after amendment, will I get the same validity or it will be reduced to 1 year.

Please let me know on this. Thanks in Advance !!!