The severance package Google gave to 12,000 employees it laid off on Jan. 20 was among the best in the tech industry, but it wasn’t as good as many of the affected employees were initially told.

Google on Thursday notified soon-to-be former employees in the U.S. that it had incorrectly calculated the number of the stock grants many of them would receive, according to a copy of an email viewed by The Information. The result: some laid-off employees are getting tens or even hundreds of thousands of dollars less than they were told in an earlier layoff email from the company.