Advance Update Statement Sql Server

I am trying to speed up my update statements by removing inner select
statements.

Example:
update orders set shipname = (select contactName from
customers where customerid = orders.customerID)

I read some articles which said that I should be able to use an inner
join on the update statement like the following:


update orders set shipname = (select contactName from customers where
customerid = orders.customerID)

But every time that I run this statement I get the follwing error:
Server: Msg 156, Level 15, State 1, Line 1
Incorrect syntax near the keyword 'inner'.

Any Help will be greatly appreciated.

Thank you.