diff --git a/sys/dev/virtio/balloon/virtio_balloon.c b/sys/dev/virtio/balloon/virtio_balloon.c
index bf4e5cf916f..966a715f798 100644
--- a/sys/dev/virtio/balloon/virtio_balloon.c
+++ b/sys/dev/virtio/balloon/virtio_balloon.c
@@ -413,7 +413,7 @@ vtballoon_send_page_frames(struct vtballoon_softc *sc, struct virtqueue *vq,
 	struct sglist sg;
 	struct sglist_seg segs[1];
 	void *c;
-	int error;
+	int error __diagused;
 
 	sglist_init(&sg, 1, segs);
 
diff --git a/sys/dev/virtio/scsi/virtio_scsi.c b/sys/dev/virtio/scsi/virtio_scsi.c
index adf4fd17fc5..d152e327365 100644
--- a/sys/dev/virtio/scsi/virtio_scsi.c
+++ b/sys/dev/virtio/scsi/virtio_scsi.c
@@ -1795,7 +1795,7 @@ vtscsi_transport_reset_event(struct vtscsi_softc *sc,
 static void
 vtscsi_handle_event(struct vtscsi_softc *sc, struct virtio_scsi_event *event)
 {
-	int error;
+	int error __diagused;
 
 	if ((event->event & VIRTIO_SCSI_T_EVENTS_MISSED) == 0) {
 		switch (event->event) {