diff --git a/plugins/sudoers/log_client.c b/plugins/sudoers/log_client.c
index 818218a3d..c926ddbe7 100644
--- a/plugins/sudoers/log_client.c
+++ b/plugins/sudoers/log_client.c
@@ -909,7 +909,9 @@ fmt_info_messages(struct client_closure *closure, struct eventlog *evlog,
     fill_str("submithost", evlog->submithost);
     /* TODO - submituid */
     fill_str("submituser", evlog->submituser);
-    fill_str("ttyname", evlog->ttyname);
+    if (evlog->ttyname != NULL) {
+	fill_str("ttyname", evlog->ttyname);
+    }
 
     /* Free unused structs. */
     while (info_msgs_size > n)