Disclosed is a method of rejuvenating a molecular sieve. The method includes contacting a molecular sieve having a methanol uptake of less than 1, or a catalyst containing molecular sieve having a methanol up of less than 1, with anhydrous liquid or vapor until the methanol uptake ratio is increased by at least 10%. The rejuvenated molecular sieve or catalyst can be used to make an olefin product from an oxygenate-containing feedstock. The preferred molecular sieve is a silicoaluminophosphate (SAPO) molecular sieve.