diff --git a/CHANGELOG b/CHANGELOG
index 0a0be69b5..b080799ed 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+* Replace array creation and `Array#include` with a more efficient `RegExp#test`. (kangax)
+
 * Make sure BUTTON elements are included in form serialization. (Luis Gomez, freshteapot, Samuel Lebeau, kangax)
 
 * Make sure (defficient) APPLET, OBJECT and EMBED elements are extended with simulated methods in IE8. Return early if _extendedByPrototype is present on an element. (Tobie Langel, kangax)
diff --git a/src/dom/form.js b/src/dom/form.js
index d2dfdd729..c521d05a8 100644
--- a/src/dom/form.js
+++ b/src/dom/form.js
@@ -163,7 +163,7 @@ Form.Methods = {
     }).sortBy(function(element) { return element.tabIndex; }).first();
     
     return firstByIndex ? firstByIndex : elements.find(function(element) {
-      return ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
+      return /^(?:input|select|textarea)$/i.test(element.tagName);
     });
   },
 
@@ -333,7 +333,7 @@ Form.Element.Methods = {
     try {
       element.focus();
       if (element.select && (element.tagName.toLowerCase() != 'input' ||
-          !['button', 'reset', 'submit'].include(element.type)))
+          !(/^(?:button|reset|submit)$/i.test(element.type))))
         element.select();
     } catch (e) { }
     return element;