diff --git a/code/controllers/subsystem/area_contents.dm b/code/controllers/subsystem/area_contents.dm
index 11e07eac55b..830c6857561 100644
--- a/code/controllers/subsystem/area_contents.dm
+++ b/code/controllers/subsystem/area_contents.dm
@@ -63,6 +63,8 @@ SUBSYSTEM_DEF(area_contents)
 				if(MC_TICK_CHECK)
 					cut_from.Cut(1, amount_cut + 1)
 					return
+			// avoid double removals if we return early on a subsequent z-level
+			clear.turfs_to_uncontain_by_zlevel[area_zlevel] = list()
 
 		clear.turfs_to_uncontain_by_zlevel = list()
 		marked_for_clearing.len--
diff --git a/code/game/world.dm b/code/game/world.dm
index 9a81e19d97f..e2370fedb1f 100644
--- a/code/game/world.dm
+++ b/code/game/world.dm
@@ -484,8 +484,8 @@ GLOBAL_VAR(restart_counter)
 	LISTASSERTLEN(global_area.turfs_by_zlevel, map_load_z_cutoff, list())
 	for (var/zlevel in 1 to map_load_z_cutoff)
 		var/list/to_add = block(
-			1, old_maxy + 1, 1,
-			maxx, maxy, map_load_z_cutoff
+			1, old_maxy + 1, zlevel,
+			maxx, maxy, zlevel
 		)
 		global_area.turfs_by_zlevel[zlevel] += to_add