diff --git a/src/kernel/region.c b/src/kernel/region.c
index 5cb86ff47..dc2fee21d 100644
--- a/src/kernel/region.c
+++ b/src/kernel/region.c
@@ -918,6 +918,8 @@ void free_region(region * r)
         unit *u = r->units;
         r->units = u->next;
         uunhash(u);
+        u->region = NULL;
+        u_setfaction(u, NULL);
         free_unit(u);
         free(u);
     }
diff --git a/src/kernel/unit.c b/src/kernel/unit.c
index d5317ec72..61cdac6c0 100644
--- a/src/kernel/unit.c
+++ b/src/kernel/unit.c
@@ -749,6 +749,7 @@ void free_units(void)
     while (deleted_units) {
         unit *u = deleted_units;
         deleted_units = deleted_units->next;
+        u_setfaction(u, NULL);
         free_unit(u);
         free(u);
     }