diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
--- a/sys/kern/kern_kthread.c
+++ b/sys/kern/kern_kthread.c
@@ -187,6 +187,7 @@
 int
 suspend_kproc(struct thread *td, int timo)
 {
+	int timeout = 0;
 	if (td->td_proc == NULL) {
 		lwkt_gettoken(&kpsus_token);
 		/* request thread pause */
@@ -194,12 +195,14 @@
 		wakeup(td);
 		while (td->td_mpflags & TDF_MP_STOPREQ) {
 			int error = tsleep(td, 0, "suspkp", timo);
-			if (error == EWOULDBLOCK)
+			if (error == EWOULDBLOCK) {
+				timeout = 1;
 				break;
+			}
 		}
 		atomic_clear_int(&td->td_mpflags, TDF_MP_STOPREQ);
 		lwkt_reltoken(&kpsus_token);
-		return(0);
+		return (timeout ? EWOULDBLOCK : 0);
 	} else {
 		return(EINVAL);	/* not a kernel thread */
 	}