diff --git a/code/datums/map_zones.dm b/code/datums/map_zones.dm
index 611835fe7580..47cd32f21344 100644
--- a/code/datums/map_zones.dm
+++ b/code/datums/map_zones.dm
@@ -412,7 +412,7 @@
 			unlink(dir)
 	parent_level.virtual_levels -= src
 	parent_level = null
-	SSidlenpcpool.idle_mobs_by_virtual_level -= "[id]"
+	LAZYREMOVE(SSmapping.virtual_z_translation, "[id]")
 	SSmapping.virtual_z_translation -= "[id]"
 	parent_map_zone.remove_virtual_level(src)
 	if(up_linkage)