diff --git a/code/game/objects/items/stacks/medical_packs.dm b/code/game/objects/items/stacks/medical_packs.dm
index ba48b3b3b60..b97266aabd7 100644
--- a/code/game/objects/items/stacks/medical_packs.dm
+++ b/code/game/objects/items/stacks/medical_packs.dm
@@ -9,6 +9,7 @@
 	throw_range = 7
 	resistance_flags = FLAMMABLE
 	max_integrity = 40
+	parent_stack = TRUE
 	var/heal_brute = 0
 	var/heal_burn = 0
 	var/self_delay = 20
diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index 1d4861b5c28..4c90397ecc1 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -31,6 +31,8 @@
 	var/table_type
 	/// If this stack has a dynamic icon_state based on amount / max_amount
 	var/dynamic_icon_state = FALSE
+	/// if true, then this item can't stack with subtypes
+	var/parent_stack = FALSE
 
 /obj/item/stack/Initialize(mapload, new_amount, merge = TRUE)
 	. = ..()
@@ -360,7 +362,7 @@
 	use(amount)
 
 /obj/item/stack/attackby(obj/item/W, mob/user, params)
-	if(istype(W, merge_type))
+	if((!parent_stack && istype(W, merge_type)) || (parent_stack && W.type == type))
 		var/obj/item/stack/S = W
 		merge(S)
 		to_chat(user, "<span class='notice'>Your [S.name] stack now contains [S.get_amount()] [S.singular_name]\s.</span>")