diff --git a/proto/acl.proto b/proto/acl.proto
index ac36ca771f9a2306a31bcba540e9e24e326cab6a..b45d46226d2706396f6d4c0e73ce72e15a75f2d5 100644
--- a/proto/acl.proto
+++ b/proto/acl.proto
@@ -46,7 +46,7 @@ message AclMatch {
   uint32 dst_port         = 6;
   uint32 start_mpls_label = 7;
   uint32 end_mpls_label   = 8;
-  string flags            = 9;
+  string tcp_flags        = 9;
 }
 
 message AclAction {