diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 50bc91dea01..5e12b1dd0eb 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -1600,10 +1600,11 @@ static void
 selfdfree(struct seltd *stp, struct selfd *sfp)
 {
 	STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
-	mtx_lock(sfp->sf_mtx);
-	if (sfp->sf_si)
+	if (sfp->sf_si != NULL) {
+		mtx_lock(sfp->sf_mtx);
 		TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
-	mtx_unlock(sfp->sf_mtx);
+		mtx_unlock(sfp->sf_mtx);
+	}
 	uma_zfree(selfd_zone, sfp);
 }