diff --git a/openflow_input/bsn_pktin_flag b/openflow_input/bsn_pktin_flag
index 034ac0a..b046024 100644
--- a/openflow_input/bsn_pktin_flag
+++ b/openflow_input/bsn_pktin_flag
@@ -45,4 +45,5 @@
     OFP_BSN_PKTIN_FLAG_L3_CPU = 0x200,
     OFP_BSN_PKTIN_FLAG_INGRESS_ACL = 0x400,
     OFP_BSN_PKTIN_FLAG_SFLOW = 0x800,
+    OFP_BSN_PKTIN_FLAG_ARP_CACHE = 0x1000,
 };