README.md in pg_serializable-3.0.1 vs README.md in pg_serializable-3.0.2

@@ -548,10 +548,10 @@
 
 class Variation < ApplicationRecord
   serializable do
     default do
       attributes :id
-      belongs_to: :color
+      belongs_to :color
     end
 
     trait :for_products do
       attributes :id
     end