Is there a workaround for an elevatr error in R?

Question

I am trying to extract elevation values for a series of coordinates using the elevatr package in R. According to one of the vignettes (https://cran.r-project.org/web/packages/elevatr/vignettes/introduction_to_elevatr.html), the following code should work:

require(sp)
require(elevatr)

ex.x <- c(-9.979167, -9.937500, -9.895833)
ex.y <- c(64.97917, 64.97917, 64.97917)
ex.df <- data.frame(x = ex.x, y = ex.y)
ex.sp <- sp::SpatialPoints(ex.df, proj4string = CRS("+proj=longlat +datum=WGS84"))

ex.epqs <- get_elev_point(EU.elev.sp, src = "epqs")

This code works up until I try to extract the elevation values, at which point it returns the following error:

Error in h(simpleError(msg, call)) : 
  error in evaluating the argument 'CRSobj' in selecting a method for function 'spTransform': NA

Does anybody know the reason this error occurs or how to fix it? Is elevatr broken or is there something else going on?