diff --git a/proto/sgx/app.proto b/proto/sgx/app.proto
index 94d0957..a41c262 100644
--- a/proto/sgx/app.proto
+++ b/proto/sgx/app.proto
@@ -72,6 +72,7 @@ message AppNodeFilters {
   string city = 6;
   string ip = 7;
   string node_pubkey = 8;
+  uint32 free_ports = 9;
 }
 
 message AppNodeListResp {