diff --git a/src/core/transport/chttp2_transport.c b/src/core/transport/chttp2_transport.c
index 1a5999959866d83ac8f534aa0e2e771b55d8e533..bd259f7ae3d989228ba920ccb6147fd441744017 100644
--- a/src/core/transport/chttp2_transport.c
+++ b/src/core/transport/chttp2_transport.c
@@ -230,7 +230,9 @@ struct transport {
   /* basic state management - what are we doing at the moment? */
   gpr_uint8 reading;
   gpr_uint8 writing;
+  /** are we calling back (via cb) with a channel-level event */
   gpr_uint8 calling_back_channel;
+  /** are we calling back any grpc_transport_op completion events */
   gpr_uint8 calling_back_ops;
   gpr_uint8 destroying;
   gpr_uint8 closed;