diff --git a/src/core/channel/client_channel.c b/src/core/channel/client_channel.c
index e05bda7f2d13526f1e89f5e55f52dfbdf47b80b5..871e970eb8d152c73e85084e811dec1124d9b530 100644
--- a/src/core/channel/client_channel.c
+++ b/src/core/channel/client_channel.c
@@ -57,7 +57,10 @@ typedef struct {
   grpc_mdctx *mdctx;
   /** resolver for this channel */
   grpc_resolver *resolver;
-  /** master channel */
+  /** master channel - the grpc_channel instance that ultimately owns
+      this channel_data via its channel stack.
+      We occasionally use this to bump the refcount on the master channel
+      to keep ourselves alive through an asynchronous operation. */
   grpc_channel *master;
 
   /** mutex protecting client configuration, including all