diff --git a/lib/new_relic/agent/transaction.rb b/lib/new_relic/agent/transaction.rb
index 08b63cbe4c..f4a3999071 100644
--- a/lib/new_relic/agent/transaction.rb
+++ b/lib/new_relic/agent/transaction.rb
@@ -37,7 +37,6 @@ class Transaction
       ACTION_CABLE_PREFIX = "#{CONTROLLER_PREFIX}ActionCable/"
 
       WEB_TRANSACTION_CATEGORIES = [:web, :controller, :uri, :rack, :sinatra, :grape, :middleware, :action_cable].freeze
-      TRANSACTION_NAMING_SOURCES = [:child, :api].freeze
 
       MIDDLEWARE_SUMMARY_METRICS = ["Middleware/all"].freeze
       WEB_SUMMARY_METRIC = "HttpDispatcher"