diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index 3dbf3e19acbe..20995223b6d2 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -1881,7 +1881,8 @@ crunuse(struct thread *td)
 {
 	struct ucred *cr, *crold;
 
-	cr = td->td_ucred;
+	MPASS(td->td_realucred == td->td_ucred);
+	cr = td->td_realucred;
 	mtx_lock(&cr->cr_mtx);
 	cr->cr_ref += td->td_ucredref;
 	td->td_ucredref = 0;
@@ -1897,6 +1898,7 @@ crunuse(struct thread *td)
 		crold = NULL;
 	}
 	mtx_unlock(&cr->cr_mtx);
+	td->td_realucred = NULL;
 	return (crold);
 }
 
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 8216c31ef0c0..37120a06d1e2 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -543,6 +543,7 @@ thread_exit(void)
 	    (long)p->p_pid, td->td_name);
 	SDT_PROBE0(proc, , , lwp__exit);
 	KASSERT(TAILQ_EMPTY(&td->td_sigqueue.sq_list), ("signal pending"));
+	MPASS(td->td_realucred == td->td_ucred);
 
 	/*
 	 * drop FPU & debug register state storage, or any other