  We discuss the signatures of a Kramers pair of Majorana modes formed in a
Josephson junction on top of a quantum spin Hall system. We show that, while
ignoring interactions on the quantum spin Hall edge allows arbitrary Andreev
process in the system, moderate repulsive interactions stabilize Andreev
transmission - the hole goes into the opposite lead from where the electron has
arrived. We analyze the renormalization group equations and deduce the
existence of a non-trivial critical point for sufficiently strong interactions.
