California Laws|Section 676.12.

                                                
676.12.  
(a) If, after an obligation is expressed or a loss is incurred in a foreign money, the country issuing or adopting that money substitutes a new money in place of that money, the obligation or the loss is treated as if expressed or incurred in the new money at the rate of conversion the issuing country establishes for the payment of like obligations or losses denominated in the former money. 
(b) If substitution under subdivision (a) occurs after a judgment or award is entered on a foreign-money claim, the court or arbitrator shall amend the judgment or award by a like
  conversion of the former money.