diff --git a/code/modules/mob/living/carbon/monkey/diona.dm b/code/modules/mob/living/carbon/monkey/diona.dm
index 44ac48debe8..84440c292b5 100644
--- a/code/modules/mob/living/carbon/monkey/diona.dm
+++ b/code/modules/mob/living/carbon/monkey/diona.dm
@@ -221,7 +221,7 @@
 	src.visible_message("\red [src] flicks out a feeler and neatly steals a sample of [M]'s blood.","\red You flick out a feeler and neatly steal a sample of [M]'s blood.")
 	donors += M.real_name
 	for(var/datum/language/L in M.languages)
-		languages += L
+		languages |= L
 
 	spawn(25)
 		update_progression()
@@ -248,4 +248,4 @@
 
 /mob/living/carbon/monkey/diona/put_in_active_hand(obj/item/W)
 	src << "\red You don't have any hands!"
-	return
\ No newline at end of file
+	return