Error using osrmIsochrone in R rCarto/osrm

Question

devtools::install_github("rCarto/osrm")

library(osrm)

iso <- osrmIsochrone(loc = c(1.300658, 103.839696), breaks = seq(from = 0,to = 30, by = 5))

Gives me the following error:

Error in spTransform(xSP, CRSobj, ...) : 
  error in pj_transform: latitude or longitude exceeded limits

Can someone please tell me what I am doing wrong, and how to fix this error? Many thanks