In a previous paper (Blado et al 2014 Eur. J. Phys. 35
[http://dx.doi.org/10.1088/0143-0807/35/6/065011] 065011 ), we showed that quantum gravity effects
can be discussed with only a background in non-relativistic quantum mechanics at the undergraduate
level by looking at the effect of the generalised uncertainty principle (GUP) on the finite and
infinite square wells. In this paper, we derive the GUP corrections to the tunnelling probability of
simple quantum mechanical systems which are accessible to undergraduates (alpha decay, simple models
of quantum cosmogenesis and gravitational tunnelling radiation) and which employ the WKB
approximation, a topic discussed in undergraduate quantum mechanics classes. It is shown that the
GUP correction increases the tunnelling probability in each of the examples discussed.