diff --git a/src/runner.c b/src/runner.c
index dddeaad7fd72721cd30b3ea31c9822bbabb85620..ba13d062612a512c8992df8ecd9c4d05414fc551 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -556,6 +556,7 @@ void runner_do_star_formation(struct runner *r, struct cell *c, int timer) {
 
 #ifdef SWIFT_DEBUG_CHECKS
           sp->ti_kick = gp->ti_kick;
+          gp->ti_drift = sp->drift;
 #endif
 
           /* Set a smoothing length */