diff --git a/dot_muttrc b/dot_muttrc
index 5964fe1..b13e4fd 100644
--- a/dot_muttrc
+++ b/dot_muttrc
@@ -21,7 +21,7 @@ set mail_check_stats
 set virtual_spoolfile=yes
 source ~/.mailboxes
 
-set use_threads=unset sort=date sort_aux=date
+set use_threads=yes sort=date sort_aux=date
 
 #### BEGIN NOTMUCH-MUTT SETTINGS
 #    macro index  \