2 files changed, 4 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/schema_migration.rb b/activerecord/lib/active_record/schema_migration.rb
index 5e484ded75..3a004d58c9 100644
--- a/activerecord/lib/active_record/schema_migration.rb
+++ b/activerecord/lib/active_record/schema_migration.rb
@@ -5,6 +5,9 @@ require 'active_record/base'
 module ActiveRecord
   class SchemaMigration < ActiveRecord::Base
     class << self
+      def primary_key
+        nil
+      end
 
       def table_name
         "#{table_name_prefix}#{ActiveRecord::Base.schema_migrations_table_name}#{table_name_suffix}"
diff --git a/activerecord/lib/active_record/type/serialized.rb b/activerecord/lib/active_record/type/serialized.rb
index 78a6d31e26..94d9d9a549 100644
--- a/activerecord/lib/active_record/type/serialized.rb
+++ b/activerecord/lib/active_record/type/serialized.rb
@@ -20,7 +20,7 @@ module ActiveRecord
       def type_cast_for_write(value)
         return if value.nil?
         unless is_default_value?(value)
-          coder.dump(value)
+          super coder.dump(value)
         end
       end