diff --git a/lib/typed/json_serializer.rb b/lib/typed/json_serializer.rb
index bb0542c..2011d14 100644
--- a/lib/typed/json_serializer.rb
+++ b/lib/typed/json_serializer.rb
@@ -7,9 +7,9 @@ class JSONSerializer < Serializer
     Input = type_member { {fixed: String} }
     Output = type_member { {fixed: String} }
 
-    sig { override.params(sourcer: Input).returns(Result[T::Struct, DeserializeError]) }
-    def deserialize(sourcer)
-      parsed_json = JSON.parse(sourcer)
+    sig { override.params(source: Input).returns(Result[T::Struct, DeserializeError]) }
+    def deserialize(source)
+      parsed_json = JSON.parse(source)
 
       creation_params = schema.fields.each_with_object(T.let({}, Params)) do |field, hsh|
         hsh[field.name] = parsed_json[field.name.to_s]