diff --git a/src/kiri/init.js b/src/kiri/init.js
index 59a40d2f..cf4ce468 100644
--- a/src/kiri/init.js
+++ b/src/kiri/init.js
@@ -1643,7 +1643,7 @@
             detail:           UC.newSelect(LANG.pt_qual_s, {title: LANG.pt_qual_l, action: detailSave}, "detail"),
             decimate:         UC.newBoolean(LANG.pt_deci_s, booleanSave, {title: LANG.pt_deci_l}),
             healMesh:         UC.newBoolean(LANG.pt_heal_s, booleanSave, {title: LANG.pt_heal_l}),
-            threaded:         UC.newBoolean(LANG.pt_thrd_s, booleanSave, {title: LANG.pt_thrd_l}),
+            threaded:         UC.newBoolean(LANG.pt_thrd_s, booleanSave, {title: LANG.pt_thrd_l, modes:FDM}),
 
             prefadd:          UC.checkpoint($('prefs-add')),