diff --git a/activesupport/lib/active_support/locale/en.yml b/activesupport/lib/active_support/locale/en.yml
index e604c9ee8c763..49ad192bf13de 100644
--- a/activesupport/lib/active_support/locale/en.yml
+++ b/activesupport/lib/active_support/locale/en.yml
@@ -15,7 +15,10 @@ en:
     month_names: [~, January, February, March, April, May, June, July, August, September, October, November, December]
     abbr_month_names: [~, Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec]
     # Used in date_select and datime_select.
-    order: [ :year, :month, :day ]
+    order:
+      - :year
+      - :month
+      - :day
 
   time:
     formats: