diff --git a/activejob/lib/active_job/core.rb b/activejob/lib/active_job/core.rb
index 19b900a285c17a65e40188a798372cc009bfbf81..0b32b7263c4eb382fcc9f05125adcf13037db52e 100644
--- a/activejob/lib/active_job/core.rb
+++ b/activejob/lib/active_job/core.rb
@@ -79,7 +79,7 @@ def serialize
         'queue_name' => queue_name,
         'priority'   => priority,
         'arguments'  => serialize_arguments(arguments),
-        'locale'     => I18n.locale
+        'locale'     => I18n.locale.to_s
       }
     end
 
diff --git a/activejob/test/cases/job_serialization_test.rb b/activejob/test/cases/job_serialization_test.rb
index 229517774e088ea9e28e0846a2ac54cd2f00b393..4c5a45b658ab99af5c8b0b69b90fb12c3ab257f3 100644
--- a/activejob/test/cases/job_serialization_test.rb
+++ b/activejob/test/cases/job_serialization_test.rb
@@ -15,13 +15,13 @@ class JobSerializationTest < ActiveSupport::TestCase
   end
 
   test 'serialize includes current locale' do
-    assert_equal :en, HelloJob.new.serialize['locale']
+    assert_equal 'en', HelloJob.new.serialize['locale']
   end
 
   test 'deserialize sets locale' do
     job = HelloJob.new
-    job.deserialize 'locale' => :es
-    assert_equal :es, job.locale
+    job.deserialize 'locale' => 'es'
+    assert_equal 'es', job.locale
   end
 
   test 'deserialize sets default locale' do