R help - Sep 2015 - dplyr complete.cases(.) works one way but not another

Hello!
I don't have a data set, but my question is very clear without it.
I have a data frame 'mydata' and want to reproduce in dplyr the
following R base command:

mydata[complete.cases(mydata), ]

This dplyr command produces the expected result:

library(dplyr)
mydata %>% filter(complete.cases(.))

But this command doesn't work:

filter(mydata, complete.cases(.))
Error: object '.' not found

Why doesn't it work?
Thank you!

-- 
Dimitri Liakhovitski