diff --git a/src/core/channel/channel_args.c b/src/core/channel/channel_args.c
index 619bdd7e99ac83c25e512ddeb4860516b86e4d37..bae7a90a0152256546dd76a5bf9fc58e4b343b4b 100644
--- a/src/core/channel/channel_args.c
+++ b/src/core/channel/channel_args.c
@@ -118,6 +118,8 @@ static int cmp_arg(const grpc_arg *a, const grpc_arg *b) {
   GPR_UNREACHABLE_CODE(return 0);
 }
 
+/* stabilizing comparison function: since channel_args ordering matters for
+ * keys with the same name, we need to preserve that ordering */
 static int cmp_key_stable(const void *ap, const void *bp) {
   const grpc_arg *const *a = ap;
   const grpc_arg *const *b = bp;