diff --git a/src/index.ts b/src/index.ts
index f1dc9b7..fdd92c6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -136,8 +136,8 @@ const DEFAULT_CARDS: string[] = [
   "You don't have to be ashamed of using your own ideas", //
 ];
 
-export const getDefaultCards = () => DEFAULT_CARDS;
+export const getDefaultCards = (): string[] => DEFAULT_CARDS;
 
-export const generate = (cards = getDefaultCards()) => (
+export const generate = (cards = getDefaultCards()): string => (
   cards[Math.floor(Math.random() * cards.length)]
 );