diff --git a/random_size.py b/random_size.py
index d9bdfce..733ade3 100644
--- a/random_size.py
+++ b/random_size.py
@@ -19,8 +19,7 @@ class RandomSize:
     def func(self:str):
         sizes = read_config('sizes')
         rand_obj = random.Random()
-        idx = rand_obj.randint(0, len(sizes))
-        size = sizes[idx]
+        size = rand_obj.choice(sizes)
         x, y = [int(v) for v in size.split('x')]
         return (x,y)