Index: src/wp-admin/js/theme.js
===================================================================
--- src/wp-admin/js/theme.js	(revision 26479)
+++ src/wp-admin/js/theme.js	(working copy)
@@ -561,7 +561,8 @@
 	className: 'theme-search',
 
 	attributes: {
-		placeholder: l10n.search
+		placeholder: l10n.search,
+		type: 'search'
 	},
 
 	events: {