diff --git a/sys/dev/usb/net/if_smsc.c b/sys/dev/usb/net/if_smsc.c
index 841353cecfa4..b642a6989616 100644
--- a/sys/dev/usb/net/if_smsc.c
+++ b/sys/dev/usb/net/if_smsc.c
@@ -1707,7 +1707,7 @@ smsc_attach_post_sub(struct usb_ether *ue)
 	/* The chip supports TCP/UDP checksum offloading on TX and RX paths, however
 	 * currently only RX checksum is supported in the driver (see top of file).
 	 */
-	ifp->if_capabilities |= IFCAP_RXCSUM;
+	ifp->if_capabilities |= IFCAP_RXCSUM | IFCAP_VLAN_MTU;
 	ifp->if_hwassist = 0;
 	
 	/* TX checksuming is disabled (for now?)