diff --git a/gammapkt.cc b/gammapkt.cc
index c8f9b34d3..7e8d95b32 100644
--- a/gammapkt.cc
+++ b/gammapkt.cc
@@ -731,12 +731,6 @@ void transport_gamma(Packet &pkt, const double t2) {
 
   const auto [sdist, snext] = grid::boundary_distance(pkt.dir, pkt.pos, pkt.prop_time, pkt.where, &pkt.last_cross);
 
-  if (((snext < 0) && (snext != -99)) || (snext >= grid::ngrid)) {
-    printout("Heading for inappropriate grid cell. Abort.\n");
-    printout("Current cell %d, target cell %d.\n", pkt.where, snext);
-    assert_always(false);
-  }
-
   // Now consider the scattering/destruction processes.
   // Compton scattering - need to determine the scattering co-efficient.
   // Routine returns the value in the rest frame.