1 files changed, 4 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 4babee07b4..6c5792954f 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -249,6 +249,10 @@ module ActiveRecord
         end
 
         class Json < Type
+          def type_cast_for_write(value)
+            ConnectionAdapters::PostgreSQLColumn.json_to_string value
+          end
+
           def type_cast(value)
             return if value.nil?