diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c
index 1185cf817f81..1bbc76cda313 100644
--- a/sys/kern/init_sysent.c
+++ b/sys/kern/init_sysent.c
@@ -459,7 +459,7 @@ struct sysent sysent[] = {
 	{ SYF_MPSAFE | AS(__acl_aclcheck_link_args), (sy_call_t *)__acl_aclcheck_link },	/* 428 = __acl_aclcheck_link */
 	{ SYF_MPSAFE | AS(sigwait_args), (sy_call_t *)sigwait },	/* 429 = sigwait */
 	{ SYF_MPSAFE | AS(thr_create_args), (sy_call_t *)thr_create },	/* 430 = thr_create */
-	{ SYF_MPSAFE | 0, (sy_call_t *)thr_exit },	/* 431 = thr_exit */
+	{ SYF_MPSAFE | AS(thr_exit_args), (sy_call_t *)thr_exit },	/* 431 = thr_exit */
 	{ SYF_MPSAFE | AS(thr_self_args), (sy_call_t *)thr_self },	/* 432 = thr_self */
 	{ SYF_MPSAFE | AS(thr_kill_args), (sy_call_t *)thr_kill },	/* 433 = thr_kill */
 	{ SYF_MPSAFE | AS(_umtx_lock_args), (sy_call_t *)_umtx_lock },	/* 434 = _umtx_lock */
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 10dac1edc789..789fd2dcdb2c 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -614,7 +614,7 @@
 		    acl_type_t type, struct acl *aclp); }
 429	MSTD	{ int sigwait(const sigset_t *set, int *sig); }
 430	MSTD	{ int thr_create(ucontext_t *ctx, long *id, int flags); }
-431	MSTD	{ void thr_exit(void); }
+431	MSTD	{ void thr_exit(long *state); }
 432	MSTD	{ int thr_self(long *id); }
 433	MSTD	{ int thr_kill(long id, int sig); }
 434	MSTD	{ int _umtx_lock(struct umtx *umtx); }
diff --git a/sys/sys/sysproto.h b/sys/sys/sysproto.h
index ff283636feca..83ee56a6c88d 100644
--- a/sys/sys/sysproto.h
+++ b/sys/sys/sysproto.h
@@ -1252,7 +1252,7 @@ struct thr_create_args {
 	char flags_l_[PADL_(int)]; int flags; char flags_r_[PADR_(int)];
 };
 struct thr_exit_args {
-	register_t dummy;
+	char state_l_[PADL_(long *)]; long * state; char state_r_[PADR_(long *)];
 };
 struct thr_self_args {
 	char id_l_[PADL_(long *)]; long * id; char id_r_[PADR_(long *)];