wow i forgot some extremely important updates haha

code/game/machinery/doors/firedoor.dm

@@ -34,6 +34,8 @@
 /obj/machinery/door/firedoor/Initialize(mapload)
 	. = ..()
 	CalculateAffectingAreas()
+	UpdateAdjacencyFlags()
+
 
 /obj/machinery/door/firedoor/examine(mob/user)
 	. = ..()
@@ -53,6 +55,20 @@
 		var/area/A = I
 		LAZYADD(A.firedoors, src)
 
+/obj/machinery/door/firedoor/proc/UpdateAdjacencyFlags()
+	var/turf/T = get_turf(src)
+	if(flags_1 & ON_BORDER_1)
+		for(var/t in T.atmos_adjacent_turfs)
+			if(get_dir(loc, t) == dir)
+				var/turf/open/T2 = t
+				T.atmos_adjacent_turfs[T2] |= ATMOS_ADJACENT_FIRELOCK
+				T2.atmos_adjacent_turfs[T] |= ATMOS_ADJACENT_FIRELOCK
+	else
+		for(var/t in T.atmos_adjacent_turfs)
+			var/turf/open/T2 = t
+			T.atmos_adjacent_turfs[T2] |= ATMOS_ADJACENT_FIRELOCK
+			T2.atmos_adjacent_turfs[T] |= ATMOS_ADJACENT_FIRELOCK
+
 /obj/machinery/door/firedoor/closed
 	icon_state = "door_closed"
 	opacity = TRUE

code/game/turfs/change_turf.dm

@@ -15,7 +15,7 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 
 	if(turf_type)
 		var/turf/newT = ChangeTurf(turf_type, baseturf_type, flags)
-		CALCULATE_ADJACENT_TURFS(newT)
+		newT.ImmediateCalculateAdjacentTurfs()
 
 /turf/proc/copyTurf(turf/T)
 	if(T.type != type)
@@ -285,10 +285,7 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 //If you modify this function, ensure it works correctly with lateloaded map templates.
 /turf/proc/AfterChange(flags) //called after a turf has been replaced in ChangeTurf()
 	levelupdate()
-	if(flags & CHANGETURF_RECALC_ADJACENT)
-		ImmediateCalculateAdjacentTurfs()
-	else
-		CALCULATE_ADJACENT_TURFS(src)
+	ImmediateCalculateAdjacentTurfs()
 
 	//update firedoor adjacency
 	var/list/turfs_to_check = get_adjacent_open_turfs(src) | src

code/game/turfs/turf.dm

@@ -75,7 +75,7 @@ GLOBAL_LIST_EMPTY(station_turfs)
 		add_overlay(/obj/effect/fullbright)
 
 	if(requires_activation)
-		CALCULATE_ADJACENT_TURFS(src)
+		ImmediateCalculateAdjacentTurfs()
 
 	if (light_power && light_range)
 		update_light()
@@ -111,7 +111,7 @@ GLOBAL_LIST_EMPTY(station_turfs)
 /turf/proc/set_temperature()
 
 /turf/proc/Initalize_Atmos(times_fired)
-	CALCULATE_ADJACENT_TURFS(src)
+	ImmediateCalculateAdjacentTurfs()
 
 /turf/Destroy(force)
 	. = QDEL_HINT_IWILLGC