Index: head/sys/dev/ixgbe/if_ix.c
===================================================================
--- head/sys/dev/ixgbe/if_ix.c
+++ head/sys/dev/ixgbe/if_ix.c
@@ -379,6 +379,7 @@
 	.isc_vendor_info = ixgbe_vendor_info_array,
 	.isc_driver_version = ixgbe_driver_version,
 	.isc_driver = &ixgbe_if_driver,
+	.isc_flags = IFLIB_TSO_INIT_IP,
 
 	.isc_nrxd_min = {MIN_RXD},
 	.isc_ntxd_min = {MIN_TXD},
Index: head/sys/dev/ixgbe/if_ixv.c
===================================================================
--- head/sys/dev/ixgbe/if_ixv.c
+++ head/sys/dev/ixgbe/if_ixv.c
@@ -220,6 +220,7 @@
 	.isc_vendor_info = ixv_vendor_info_array,
 	.isc_driver_version = ixv_driver_version,
 	.isc_driver = &ixv_if_driver,
+	.isc_flags = IFLIB_TSO_INIT_IP,
 
 	.isc_nrxd_min = {MIN_RXD},
 	.isc_ntxd_min = {MIN_TXD},
Index: head/sys/dev/ixgbe/ix_txrx.c
===================================================================
--- head/sys/dev/ixgbe/ix_txrx.c
+++ head/sys/dev/ixgbe/ix_txrx.c
@@ -131,7 +131,7 @@
 
 	switch (pi->ipi_ipproto) {
 	case IPPROTO_TCP:
-		if (pi->ipi_csum_flags & (CSUM_IP_TCP | CSUM_IP6_TCP))
+		if (pi->ipi_csum_flags & (CSUM_IP_TCP | CSUM_IP6_TCP | CSUM_TSO))
 			type_tucmd_mlhl |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
 		else
 			offload = FALSE;