diff --git a/SMODS.Center/SMODS.Booster.md b/SMODS.Center/SMODS.Booster.md
index 8368b14..f7c65d1 100644
--- a/SMODS.Center/SMODS.Booster.md
+++ b/SMODS.Center/SMODS.Booster.md
@@ -26,7 +26,7 @@
     - `select_card`:
 		- Set to string of destination card area, ex. `'consumeables'`, to save cards from the pack instead of using them.
 		- Set to table of form `{Set = 'area'}` to change behaviour according to a card's `Set` (e.g. `{Tarot = 'consumeables'}` to only save `Tarot` cards, relevant if you have multiple types of consumables in a booster).
-		- Set to a function `select_card(card, pack) -> string?` to control if and where `card` should be saved for any `card, pack` combination.
+		- Set to a function `select_card(self, card, pack) -> string?` to control if and where `card` should be saved for any `card, pack` combination.
 
 ## API methods
 - `loc_vars, generate_ui` [(reference)](https://github.com/Steamodded/smods/wiki/Localization#Localization-functions)