Index: sys/kern/subr_unit.c
===================================================================
--- sys/kern/subr_unit.c
+++ sys/kern/subr_unit.c
@@ -382,9 +382,11 @@
 		Free(up);
 		up = uq;
 	}
-	TAILQ_INIT(&uh->head);
 	uh->busy = 0;
 	uh->alloc = 0;
+	init_unrhdr(uh, uh->low, uh->high, uh->mtx);
+
+	check_unrhdr(uh, __LINE__);
 }
 
 static __inline int