diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
index aff0fe6a1c37..cb231c8c6558 100644
--- a/sys/kern/kern_kthread.c
+++ b/sys/kern/kern_kthread.c
@@ -254,7 +254,10 @@ kthread_add(void (*func)(void *), void *arg, struct proc *p,
 		p = &proc0;
 		oldtd = &thread0;
 	} else {
-		oldtd = FIRST_THREAD_IN_PROC(p);
+		if (p == &proc0)
+			oldtd = &thread0;
+		else
+			oldtd = FIRST_THREAD_IN_PROC(p);
 	}
 
 	/* Initialize our td  */
@@ -315,7 +318,7 @@ kthread_add(void (*func)(void *), void *arg, struct proc *p,
 }
 
 void
-kthread_exit(int ecode)
+kthread_exit(void)
 {
 	thread_exit();
 }
diff --git a/sys/sys/kthread.h b/sys/sys/kthread.h
index 2bd4b33bb36a..e4d9c5a9a5be 100644
--- a/sys/sys/kthread.h
+++ b/sys/sys/kthread.h
@@ -68,7 +68,7 @@ int     kproc_kthread_add(void (*)(void *), void *,
 int     kthread_add(void (*)(void *), void *,
 	    struct proc *, struct thread **,
 	    int flags, int pages, const char *, ...) __printflike(7, 8);
-void    kthread_exit(int) __dead2;
+void    kthread_exit(void) __dead2;
 int	kthread_resume(struct thread *);
 void	kthread_shutdown(void *, int);
 void	kthread_start(const void *);