diff --git a/app/main.py b/app/main.py
index 62f88adc..25d4a7ef 100644
--- a/app/main.py
+++ b/app/main.py
@@ -31,5 +31,5 @@ def bring_slippers(self) -> None:
         print("The slippers delivered!")
 
 
-def feed_animals(list_animals: list["Animal"]) -> int:
+def feed_animals(list_animals: list[Animal]) -> int:
     return sum(animal.feed() for animal in list_animals)