diff --git a/src/space.c b/src/space.c
index 432f26621da978e9cea882b10934dfe9412112cc..86c8cc36eacd58c89181831b3c5472026281043c 100644
--- a/src/space.c
+++ b/src/space.c
@@ -399,6 +399,7 @@ void space_regrid(struct space *s, double cell_max, int verbose) {
       s->cells_top[k].density = NULL;
       s->cells_top[k].gradient = NULL;
       s->cells_top[k].force = NULL;
+      s->cells_top[k].grav = NULL;
       s->cells_top[k].dx_max = 0.0f;
       s->cells_top[k].sorted = 0;
       s->cells_top[k].count = 0;