Index: src/wp-includes/js/tinymce/skins/wordpress/wp-content.css
===================================================================
--- src/wp-includes/js/tinymce/skins/wordpress/wp-content.css	(revision 38327)
+++ src/wp-includes/js/tinymce/skins/wordpress/wp-content.css	(working copy)
@@ -20,7 +20,8 @@
 	font-family: Tahoma, "Times New Roman", "Bitstream Charter", Times, serif;
 }
 
-body.locale-he-il {
+body.locale-he-il,
+body.locale-vi {
 	font-family: Arial, "Times New Roman", "Bitstream Charter", Times, serif;
 }