### can gridlines be painted at sqrt(2) ?

In this simple plot

plot(x,0,2,gridlines=([1],[]))

the gridline is plotted alright. However, if I put sqrt(2) instead of 1

plot(x,0,2,gridlines=([sqrt(2)],[]))

does not work. It is strange, because I think that gridlines should behave similar as ticks. For instance, the following both two expressions work

plot(x,0,2,ticks=([sqrt(2)],[]))
plot(x,0,2,ticks=([sqrt(2)],[]),gridlines=true)

Does anybody know what is the reason or how to fix it?
Thanks.
Javier PĂ©rez.