diff --git a/activesupport/lib/active_support/railtie.rb b/activesupport/lib/active_support/railtie.rb
index 7970d39faf..c2deba3b1b 100644
--- a/activesupport/lib/active_support/railtie.rb
+++ b/activesupport/lib/active_support/railtie.rb
@@ -25,14 +25,16 @@ class Railtie < Rails::Railtie
         if defaults.key?(env)
           msg = "You did not specify how you would like Rails to report " \
                 "deprecation notices for your #{env} environment, please " \
-                "set it to :#{defaults[env]} at config/environments/#{env}.rb"
+                "set config.active_support.deprecation to :#{defaults[env]} " \
+                "at config/environments/#{env}.rb"
 
           warn msg
           ActiveSupport::Deprecation.behavior = defaults[env]
         else
           msg = "You did not specify how you would like Rails to report " \
                 "deprecation notices for your #{env} environment, please " \
-                "set it to :log, :notify or :stderr at config/environments/#{env}.rb"
+                "set config.active_support.deprecation to :log, :notify or " \
+                ":stderr at config/environments/#{env}.rb"
 
           warn msg
           ActiveSupport::Deprecation.behavior = :stderr
@@ -55,4 +57,4 @@ class Railtie < Rails::Railtie
       Time.zone_default = zone_default
     end
   end
-end
\ No newline at end of file
+end