diff --git a/common/constants.cc b/common/constants.cc
index fd2b542..c3556f8 100644
--- a/common/constants.cc
+++ b/common/constants.cc
@@ -92,5 +92,6 @@
 const char kPayloadPropertyAuthorization[] = "AUTHORIZATION";
 const char kPayloadPropertyUserAgent[] = "USER_AGENT";
 const char kPayloadPropertyPowerwash[] = "POWERWASH";
+const char kPayloadPropertyNetworkId[] = "NETWORK_ID";
 
 }  // namespace chromeos_update_engine