diff --git a/code/modules/reagents/reagent_containers.dm b/code/modules/reagents/reagent_containers.dm
index 09f595b93d2..8f3bc31d069 100644
--- a/code/modules/reagents/reagent_containers.dm
+++ b/code/modules/reagents/reagent_containers.dm
@@ -4,11 +4,11 @@
 	icon = 'icons/obj/medical/chemical.dmi'
 	icon_state = null
 	w_class = WEIGHT_CLASS_TINY
-	/// The maximum amount of reagents per transfer that will be moved out of this reagent container
+	/// The maximum amount of reagents per transfer that will be moved out of this reagent container. This value's position in possible_transfer_amounts should be reflected in amount_list_position.
 	var/amount_per_transfer_from_this = 5
 	/// The different possible amounts of reagent to transfer out of the container
 	var/list/possible_transfer_amounts = list(5,10,15,20,25,30)
-	/// Where we are in the possible transfer amount list.
+	/// Where we are in the possible transfer amount list. Number should match the position in possible_transfer_amounts corresponding to amount_per_transfer_from_this.
 	var/amount_list_position = 1
 	/// The maximum amount of reagents this container can hold
 	var/volume = 30
diff --git a/code/modules/reagents/reagent_containers/cups/_cup.dm b/code/modules/reagents/reagent_containers/cups/_cup.dm
index 8e0b254a2e0..45c2f00528b 100644
--- a/code/modules/reagents/reagent_containers/cups/_cup.dm
+++ b/code/modules/reagents/reagent_containers/cups/_cup.dm
@@ -2,6 +2,7 @@
 	name = "open container"
 	amount_per_transfer_from_this = 10
 	possible_transfer_amounts = list(5, 10, 15, 20, 25, 30, 50)
+	amount_list_position = 2
 	volume = 50
 	reagent_flags = OPENCONTAINER | DUNKABLE
 	spillable = TRUE
diff --git a/code/modules/reagents/reagent_containers/dropper.dm b/code/modules/reagents/reagent_containers/dropper.dm
index 2a005d27826..fd6397ec5f5 100644
--- a/code/modules/reagents/reagent_containers/dropper.dm
+++ b/code/modules/reagents/reagent_containers/dropper.dm
@@ -6,6 +6,7 @@
 	inhand_icon_state = "dropper"
 	worn_icon_state = "pen"
 	amount_per_transfer_from_this = 5
+	amount_list_position = 5
 	possible_transfer_amounts = list(1, 2, 3, 4, 5)
 	volume = 5
 	reagent_flags = TRANSPARENT