diff --git a/drivers/net/ethernet/marvell/octeontx2/af/npc.h b/drivers/net/ethernet/marvell/octeontx2/af/npc.h
index dc34e564c919..46689d95254b 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/npc.h
+++ b/drivers/net/ethernet/marvell/octeontx2/af/npc.h
@@ -54,8 +54,13 @@ enum npc_kpu_lb_ltype {
 	NPC_LT_LB_CUSTOM1 = 0xF,
 };
 
+/* Don't modify ltypes up to IP6_EXT, otherwise length and checksum of IP
+ * headers may not be checked correctly. IPv4 ltypes and IPv6 ltypes must
+ * differ only at bit 0 so mask 0xE can be used to detect extended headers.
+ */
 enum npc_kpu_lc_ltype {
-	NPC_LT_LC_IP = 1,
+	NPC_LT_LC_PTP = 1,
+	NPC_LT_LC_IP,
 	NPC_LT_LC_IP_OPT,
 	NPC_LT_LC_IP6,
 	NPC_LT_LC_IP6_EXT,
@@ -63,7 +68,6 @@ enum npc_kpu_lc_ltype {
 	NPC_LT_LC_RARP,
 	NPC_LT_LC_MPLS,
 	NPC_LT_LC_NSH,
-	NPC_LT_LC_PTP,
 	NPC_LT_LC_FCOE,
 	NPC_LT_LC_CUSTOM0 = 0xE,
 	NPC_LT_LC_CUSTOM1 = 0xF,