diff --git a/src/or/dirserv.c b/src/or/dirserv.c
index b6a47411b..655117ee7 100644
--- a/src/or/dirserv.c
+++ b/src/or/dirserv.c
@@ -702,7 +702,8 @@ dirserv_add_descriptor(routerinfo_t *ri, const char **msg)
     return r == -1 ? 0 : -1;
   } else {
     smartlist_t *changed;
-    control_event_or_authdir_new_descriptor("ACCEPTED", desc, desclen, *msg);
+    if (desc)
+      control_event_or_authdir_new_descriptor("ACCEPTED", desc, desclen, *msg);
 
     changed = smartlist_create();
     smartlist_add(changed, ri);