diff --git a/activesupport/lib/active_support/values/time_zone.rb b/activesupport/lib/active_support/values/time_zone.rb
index 1dfbcd11b0622d942b63c45c7609780fb4aa7958..da8808cb2169e5e2d2866f9099a6c858369c9af8 100644
--- a/activesupport/lib/active_support/values/time_zone.rb
+++ b/activesupport/lib/active_support/values/time_zone.rb
@@ -168,8 +168,7 @@ class TimeZone
       "Auckland"                     => "Pacific/Auckland",
       "Wellington"                   => "Pacific/Auckland",
       "Nuku'alofa"                   => "Pacific/Tongatapu"
-    }.each { |name, zone| name.freeze; zone.freeze }
-    MAPPING.freeze
+    }
 
     UTC_OFFSET_WITH_COLON = '%s%02d:%02d'
     UTC_OFFSET_WITHOUT_COLON = UTC_OFFSET_WITH_COLON.sub(':', '')