diff --git a/code/game/objects/structures/tank_dispenser.dm b/code/game/objects/structures/tank_dispenser.dm
index f430f94ab87..9fc69686953 100644
--- a/code/game/objects/structures/tank_dispenser.dm
+++ b/code/game/objects/structures/tank_dispenser.dm
@@ -62,7 +62,7 @@
 /obj/structure/dispenser/attack_ghost(mob/user)
 	ui_interact(user)
 
-/obj/structure/dispenser/ui_interact(mob/user, ui_key = "main", datum/nanoui/ui = null, force_open = 1, var/master_ui = null, var/datum/topic_state/state = default_state)
+/obj/structure/dispenser/ui_interact(mob/user, ui_key = "main", datum/nanoui/ui = null, force_open = 1, master_ui = null, datum/topic_state/state = GLOB.default_state)
 	user.set_machine(src)
 	ui = SSnanoui.try_update_ui(user, src, ui_key, ui, force_open)
 	if(!ui)