diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index 4e8bee8a99..bf181009a8 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -354,14 +354,6 @@ function redirect_canonical($requested_url=null, $do_redirect=true) {
 		$requested_url = preg_replace_callback('|%[a-fA-F0-9][a-fA-F0-9]|', 'lowercase_octets', $requested_url);
 	}
 
-	// Hex encoded octets are case-insensitive.
-	if ( false !== strpos($requested_url, '%') ) {
-		function lowercase_octets($matches) {
-			return strtolower($matches[0]);
-		}
-		$requested_url = preg_replace_callback('|%[a-fA-F0-9][a-fA-F0-9]|', 'lowercase_octets', $requested_url);
-	}
-
 	// Note that you can use the "redirect_canonical" filter to cancel a canonical redirect for whatever reason by returning FALSE
 	$redirect_url = apply_filters('redirect_canonical', $redirect_url, $requested_url);