diff --git a/wp-includes/compat.php b/wp-includes/compat.php
index 19a824550..acb14ed23 100644
--- a/wp-includes/compat.php
+++ b/wp-includes/compat.php
@@ -6,100 +6,7 @@
  * @access private
  */
 
-/* Added in PHP 4.2.0 */
-
-if (!function_exists('floatval')) {
-	function floatval($string) {
-		return ((float) $string);
-	}
-}
-
-if (!function_exists('is_a')) {
-	function is_a($object, $class) {
-		// by Aidan Lister <aidan@php.net>
-		if (get_class($object) == strtolower($class)) {
-			return true;
-		} else {
-			return is_subclass_of($object, $class);
-		}
-	}
-}
-
-if (!function_exists('ob_clean')) {
-	function ob_clean() {
-		// by Aidan Lister <aidan@php.net>
-		if (@ob_end_clean()) {
-			return ob_start();
-		}
-		return false;
-	}
-}
-
-
-/* Added in PHP 4.3.0 */
-
-function printr($var, $do_not_echo = false) {
-	// from php.net/print_r user contributed notes
-	ob_start();
-	print_r($var);
-	$code =  htmlentities(ob_get_contents());
-	ob_clean();
-	if (!$do_not_echo) {
-		echo "<pre>$code</pre>";
-	}
-	ob_end_clean();
-	return $code;
-}
-
-/* compatibility with PHP versions older than 4.3 */
-if ( !function_exists('file_get_contents') ) {
-	function file_get_contents( $file ) {
-		$file = file($file);
-		return !$file ? false : implode('', $file);
-	}
-}
-
-if (!defined('CASE_LOWER')) {
-		define('CASE_LOWER', 0);
-}
-
-if (!defined('CASE_UPPER')) {
-		define('CASE_UPPER', 1);
-}
-
-
-/**
- * Replace array_change_key_case()
- *
- * @category    PHP
- * @package     PHP_Compat
- * @link        http://php.net/function.array_change_key_case
- * @author      Stephan Schmidt <schst@php.net>
- * @author      Aidan Lister <aidan@php.net>
- * @version     $Revision$
- * @since       PHP 4.2.0
- * @require     PHP 4.0.0 (user_error)
- */
-if (!function_exists('array_change_key_case')) {
-		function array_change_key_case($input, $case = CASE_LOWER)
-		{
-				if (!is_array($input)) {
-						user_error('array_change_key_case(): The argument should be an array',
-								E_USER_WARNING);
-						return false;
-				}
-
-				$output   = array ();
-				$keys     = array_keys($input);
-				$casefunc = ($case == CASE_LOWER) ? 'strtolower' : 'strtoupper';
-
-				foreach ($keys as $key) {
-						$output[$casefunc($key)] = $input[$key];
-				}
-
-				return $output;
-		}
-}
+// Added in PHP 5.0
 
 if (!function_exists('http_build_query')) {
 	function http_build_query($data, $prefix=null, $sep=null) {
@@ -143,7 +50,6 @@ if ( !function_exists('_') ) {
 	}
 }
 
-// Added in PHP 5.0
 if (!function_exists('stripos')) {
 	function stripos($haystack, $needle, $offset = 0) {
 		return strpos(strtolower($haystack), strtolower($needle), $offset);
@@ -171,20 +77,4 @@ function hash_hmac($algo, $data, $key, $raw_output = false) {
 }
 endif;
 
-// Added in PHP 4.3.0?
-if (!defined('IMAGETYPE_GIF'))
-    define('IMAGETYPE_GIF', 1);
-
-if (!defined('IMAGETYPE_JPEG'))
-    define('IMAGETYPE_JPEG', 2);
-
-if (!defined('IMAGETYPE_PNG'))
-    define('IMAGETYPE_PNG', 3);
-
-if (!defined('IMAGETYPE_TIFF_MM'))
-	define('IMAGETYPE_TIFF_MM',7);
-
-if (!defined('IMAGETYPE_TIFF_MM'))
-	define('IMAGETYPE_TIFF_MM',8);
-
 ?>