diff --git a/src/core/lib/surface/init_secure.cc b/src/core/lib/surface/init_secure.cc
index 9700f43a55d..28c6f7b121f 100644
--- a/src/core/lib/surface/init_secure.cc
+++ b/src/core/lib/surface/init_secure.cc
@@ -67,6 +67,9 @@ static bool maybe_prepend_server_auth_filter(
 }
 
 void grpc_register_security_filters(void) {
+  // Register the auth client with a priority < INT_MAX to allow the authority
+  // filter -on which the auth filter depends- to be higher on the channel
+  // stack.
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL, INT_MAX - 1,
                                    maybe_prepend_client_auth_filter, nullptr);
   grpc_channel_init_register_stage(GRPC_CLIENT_DIRECT_CHANNEL, INT_MAX - 1,