diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index 69a713fac6..6bf32210bd 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -339,7 +339,7 @@
 			return
 		//get amount from user
 		var/max = get_amount()
-		var/stackmaterial = round(input(user,"How many sheets do you wish to take out of this stack? (Maximum  [max])") as num)
+		var/stackmaterial = round(input(user,"How many sheets do you wish to take out of this stack? (Maximum  [max])") as null|num)
 		max = get_amount()
 		stackmaterial = min(max, stackmaterial)
 		if(stackmaterial == null || stackmaterial <= 0 || !user.canUseTopic(src, BE_CLOSE, ismonkey(user)))
@@ -415,4 +415,4 @@
 
 /datum/stack_recipe_list/New(title, recipes)
 	src.title = title
-	src.recipes = recipes
+	src.recipes = recipes
\ No newline at end of file