behavior change of the pretty printer

Hi, Testing a package with GHC head on Travis CI, I got the following error: ---- expected: Just (HTTPDate {hdYear = 1994, hdMonth = 11, hdDay = 15, hdHour = 8, hdMinute = 12, hdSecond = 31, hdWkday = 2}) but got: Just HTTPDate {hdYear = 1994, hdMonth = 11, hdDay = 15, hdHour = 8, hdMinute = 12, hdSecond = 31, hdWkday = 2} ---- That is, parentheses are not printed. Is this an intentional change of GHC head? --Kazu