diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index 9630f170f1..dd3a890a2b 100644
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -4779,7 +4779,13 @@ guards_choose_dirguard(dirinfo_type_t info,
   if (get_options()->UseDeprecatedGuardAlgorithm) {
     return choose_random_dirguard(info);
   } else {
-    // XXXX prop271 look at info?
+    /* XXXX prop271 We don't need to look at the dirinfo_type_t here,
+     * apparently. If you look at the old implementation, and you follow info
+     * downwards through choose_random_dirguard(), into
+     * choose_random_entry_impl(), into populate_live_entry_guards()... you
+     * find out that it isn't even used, and hasn't been since 0.2.7.1-alpha,
+     * when we realized that every Tor on the network would support
+     * microdescriptors. -NM */
     const node_t *r = NULL;
     if (entry_guard_pick_for_circuit(get_guard_selection_info(),
                                      &r,