diff --git a/data/conf/dovecot/dovecot-fts-flatcurve.conf b/data/conf/dovecot/dovecot-fts-flatcurve.conf
index db981831..6b0b6c16 100644
--- a/data/conf/dovecot/dovecot-fts-flatcurve.conf
+++ b/data/conf/dovecot/dovecot-fts-flatcurve.conf
@@ -15,7 +15,7 @@ plugin {
   fts_flatcurve_optimize_limit = 10
   fts_flatcurve_rotate_size = 5000
   fts_flatcurve_rotate_time = 5000
-  fts_flatcurve_substring_search = no
+  fts_flatcurve_substring_search = yes
 }
 
 service indexer-worker {