diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c
index 181e62839251..b9ff07d95c2f 100644
--- a/sys/kern/kern_intr.c
+++ b/sys/kern/kern_intr.c
@@ -63,6 +63,7 @@ ithread_priority(flags)
 {
 	int pri;
 
+	flags &= ~INTR_MPSAFE;
 	switch (flags) {
 	case INTR_TYPE_TTY:             /* keyboard or parallel port */
 		pri = PI_TTYLOW;