diff --git a/code/modules/overmap/_defines.dm b/code/modules/overmap/_defines.dm
index c81cbb1ae67..23b6e588459 100644
--- a/code/modules/overmap/_defines.dm
+++ b/code/modules/overmap/_defines.dm
@@ -22,17 +22,18 @@ proc/toggle_move_stars(zlevel, direction)
 
 	if (moving_levels["zlevel"] != gen_dir)
 		moving_levels["zlevel"] = gen_dir
-		for(var/turf/space/S in world)
-			if(S.z == zlevel)
+		for(var/x = 1 to world.maxx)
+			for(var/y = 1 to world.maxy)
 				spawn(0)
-					var/turf/T = S
-					if(!gen_dir)
-						T.icon_state = "[((T.x + T.y) ^ ~(T.x * T.y) + T.z) % 25]"
-					else
-						T.icon_state = "speedspace_[gen_dir]_[rand(1,15)]"
-						for(var/atom/movable/AM in T)
-							if (!AM.anchored)
-								AM.throw_at(get_step(T,reverse_direction(direction)), 5, 1)
+					var/turf/space/T = locate(x,y,zlevel)
+					if (T)
+						if(!gen_dir)
+							T.icon_state = "[((T.x + T.y) ^ ~(T.x * T.y) + T.z) % 25]"
+						else
+							T.icon_state = "speedspace_[gen_dir]_[rand(1,15)]"
+							for(var/atom/movable/AM in T)
+								if (!AM.anchored)
+									AM.throw_at(get_step(T,reverse_direction(direction)), 5, 1)
 
 
 //list used to cache empty zlevels to avoid nedless map bloat