diff --git a/recipes/rollbar.rb b/recipes/rollbar.rb
index 2934825..ee6dd46 100644
--- a/recipes/rollbar.rb
+++ b/recipes/rollbar.rb
@@ -10,9 +10,7 @@ def init_file
       Rollbar.configure do |config|
         config.access_token = ENV['ROLLBAR_ACCESS_TOKEN']
         config.environment = ENV['ROLLBAR_ENV'] || Rails.env
-        config.exception_level_filters.merge!(
-          'ActionController::RoutingError': 'ignore'
-        )
+        config.exception_level_filters['ActionController::RoutingError'] = 'ignore'
 
         if Rails.env.test? || Rails.env.development?
           config.enabled = false