Adding columns to an XTS

If you're using rollapply with an existing XTS object from getSymbols what's the most appropriate way to add new columns to the object?

say you have

getSymbols('AAPL')
change = rollapply(Cl(AAPL),width=2, function(x) log(x[2]/x[1]), by=1, align = "right", na.pad = TRUE)
colnames(change) <- c('AAPL.change')

how can you get change into the original AAPL xts object whereby everything is lined up correctly?