Programs segfault in absence of occurs check

[4y8]

The following program compiles with v3.1.3 of koka:

fun g()
  fn () g()

fun main()
  println(g()() + 1)

But it segfaults when executed.
The type inferred for g is: forall<a,e> () -> div (() -> e a), which does not capture the fact that a and (() -> e a) should be the same type.