diff --git a/code/datums/elements/uses_girder_wall_recipes.dm b/code/datums/elements/uses_girder_wall_recipes.dm
index b313f78200e..38593f89f54 100644
--- a/code/datums/elements/uses_girder_wall_recipes.dm
+++ b/code/datums/elements/uses_girder_wall_recipes.dm
@@ -82,6 +82,8 @@
 	structure.add_fingerprint(user)
 	stack.add_fingerprint(user)
 
+	// Save refernce to the materials for the case when we place last tile in the stack
+	var/list/saved_mats_per_unit = stack.mats_per_unit
 	if (!stack.use_tool(structure, user, recipe.make_delay, recipe.stack_amount, extra_checks = CALLBACK(src, PROC_REF(check_recipe), structure, user, recipe)))
 		return
 
@@ -103,7 +105,7 @@
 	qdel(structure)
 
 	if (is_material_recipe)
-		wall.set_custom_materials(stack.mats_per_unit, recipe.stack_amount)
+		wall.set_custom_materials(saved_mats_per_unit, recipe.stack_amount)
 
 /// Checks if the user can do the wall recipe.
 /datum/element/uses_girder_wall_recipes/proc/check_recipe(obj/structure/structure, mob/living/user, datum/girder_wall_recipe/recipe)
diff --git a/code/game/objects/items/stacks/tiles/tile_types.dm b/code/game/objects/items/stacks/tiles/tile_types.dm
index c8f2c59d7c3..915fbf2af5e 100644
--- a/code/game/objects/items/stacks/tiles/tile_types.dm
+++ b/code/game/objects/items/stacks/tiles/tile_types.dm
@@ -1162,9 +1162,11 @@
 	merge_type = /obj/item/stack/tile/material
 
 /obj/item/stack/tile/material/place_tile(turf/open/target_plating, mob/user)
+	// Save refernce to the materials for the case when we place last tile in the stack
+	var/list/saved_mats_per_unit = mats_per_unit
 	. = ..()
 	var/turf/open/floor/material/floor = .
-	floor?.set_custom_materials(mats_per_unit)
+	floor?.set_custom_materials(saved_mats_per_unit)
 
 /obj/item/stack/tile/eighties
 	name = "retro tile"