diff --git a/sys/dev/sis/if_sis.c b/sys/dev/sis/if_sis.c
index ef95b0863d06..33eb9205d8f5 100644
--- a/sys/dev/sis/if_sis.c
+++ b/sys/dev/sis/if_sis.c
@@ -1940,7 +1940,7 @@ sis_encap(struct sis_softc *sc, struct mbuf **m_head)
 	map = txd->tx_dmamap;
 	txd->tx_dmamap = sc->sis_txdesc[prod].tx_dmamap;
 	sc->sis_txdesc[prod].tx_dmamap = map;
-	txd->tx_m = *m_head;
+	sc->sis_txdesc[prod].tx_m = *m_head;
 
 	return (0);
 }