diff --git a/sfe_ipv4.h b/sfe_ipv4.h
index 01baf2e..bdfd72d 100644
--- a/sfe_ipv4.h
+++ b/sfe_ipv4.h
@@ -53,6 +53,8 @@
 					/* remark priority of SKB */
 #define SFE_IPV4_CONNECTION_MATCH_FLAG_DSCP_REMARK (1<<6)
 					/* remark DSCP of packet */
+#define SFE_IPV4_CONNECTION_MATCH_FLAG_CSUM_OFFLOAD (1<<7)
+					/* checksum offload.*/
 
 /*
  * IPv4 connection matching structure.