diff --git a/GETTING_STARTED.md b/GETTING_STARTED.md
index 068b4730..16f8bae3 100644
--- a/GETTING_STARTED.md
+++ b/GETTING_STARTED.md
@@ -1872,6 +1872,10 @@ class JsonStrategy
   def result(evaluation)
     @strategy.result(evaluation).to_json
   end
+
+  def to_sym
+    :json
+  end
 end
 ```
 
@@ -1912,6 +1916,10 @@ class JsonStrategy
       evaluation.notify(:make_json_awesome, json)
     end
   end
+
+  def to_sym
+    :json
+  end
 end
 
 FactoryBot.register_strategy(:json, JsonStrategy)