tk_augment_fourier() not working with yearmon date format

[pepenudalg]

tk_augment_fourier() results in the following error when the date column is formatted as yearmon:

Error in charToDate(x) : character string is not in a standard unambiguous format

Reproducible example:

library(tidyverse)  
library(timetk)  
library(zoo)  
t <- data.frame(date = seq.Date(from = ymd("2010-01-01"),
                                to = ymd("2020-01-01"),
                                by = "month")) %>%
           mutate(date = as.yearmon(date)) %>% 
  tk_augment_fourier(.date_var = date, .periods = 12,  .K = 3)
t

I am using timetk_2.8.3