diff --git a/src/cell.c b/src/cell.c
index d17ba527a3d9f7960a7740e7f517d37ec015d5cc..64af8e146a266987006c4d6fbe4b70c5f0013936 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -129,7 +129,6 @@ int cell_unpack(struct pcell *pc, struct cell *c, struct space *s) {
       temp->dx_max = 0.f;
       temp->nodeID = c->nodeID;
       temp->parent = c;
-      temp->ti_old = c->ti_old;
       c->progeny[k] = temp;
       c->split = 1;
       count += cell_unpack(&pc[pc->progeny[k]], temp, s);
diff --git a/src/runner.c b/src/runner.c
index 17309d2c8c7e3517e20f7692ff77fab44b85601f..1daaded6a051b4aa84fcc3770c77740329044fe7 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -1222,15 +1222,18 @@ void runner_do_recv_cell(struct runner *r, struct cell *c, int timer) {
     for (size_t k = 0; k < nr_parts; k++) {
       const integertime_t ti_end =
           get_integer_time_end(ti_current, parts[k].time_bin);
-      // if(ti_end < ti_current) error("Received invalid particle !");
       ti_end_min = min(ti_end_min, ti_end);
       ti_end_max = max(ti_end_max, ti_end);
       h_max = max(h_max, parts[k].h);
+
+#ifdef SWIFT_DEBUG_CHECKS
+      if(parts[k].ti_drift != ti_current)
+	error("Received un-drifted particle !");
+#endif
     }
     for (size_t k = 0; k < nr_gparts; k++) {
       const integertime_t ti_end =
           get_integer_time_end(ti_current, gparts[k].time_bin);
-      // if(ti_end < ti_current) error("Received invalid particle !");
       ti_end_min = min(ti_end_min, ti_end);
       ti_end_max = max(ti_end_max, ti_end);
     }