diff --git a/NEWS b/NEWS
index ac6ffa5c..51a42359 100644
--- a/NEWS
+++ b/NEWS
@@ -25,6 +25,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
   this out.
 - Fix validation errors in configuration form
 - Hammer out a bunch of edge-case bugs in the standalone distribution
+- Inclusion reflection removed from URISchemeRegistry; you must manually
+  include any new schema files you wish to use
 . Unit test refactoring for one logical test per test function
 . Config and context parameters in ComplexHarness deprecated: instead, edit
   the $config and $context member variables
diff --git a/library/HTMLPurifier/URISchemeRegistry.php b/library/HTMLPurifier/URISchemeRegistry.php
index 8cddb7f9..6837fada 100644
--- a/library/HTMLPurifier/URISchemeRegistry.php
+++ b/library/HTMLPurifier/URISchemeRegistry.php
@@ -1,5 +1,12 @@
 <?php
 
+require_once 'HTMLPurifier/URIScheme/http.php';
+require_once 'HTMLPurifier/URIScheme/https.php';
+require_once 'HTMLPurifier/URIScheme/mailto.php';
+require_once 'HTMLPurifier/URIScheme/ftp.php';
+require_once 'HTMLPurifier/URIScheme/nntp.php';
+require_once 'HTMLPurifier/URIScheme/news.php';
+
 HTMLPurifier_ConfigSchema::define(
     'URI', 'AllowedSchemes', array(
         'http'  => true, // "Hypertext Transfer Protocol", nuf' said
@@ -7,7 +14,6 @@ HTMLPurifier_ConfigSchema::define(
         // quite useful, but not necessary
         'mailto' => true,// Email
         'ftp'   => true, // "File Transfer Protocol"
-        'irc'   => true, // "Internet Relay Chat", usually needs another app
         // for Usenet, these two are similar, but distinct
         'nntp'  => true, // individual Netnews articles
         'news'  => true  // newsgroup or individual Netnews articles
@@ -54,12 +60,6 @@ class HTMLPurifier_URISchemeRegistry
      */
     var $schemes = array();
     
-    /**
-     * Directory where scheme objects can be found
-     * @private
-     */
-    var $_scheme_dir = null;
-    
     /**
      * Retrieves a scheme validator object
      * @param $scheme String scheme name like http or mailto
@@ -79,21 +79,16 @@ class HTMLPurifier_URISchemeRegistry
         }
         
         if (isset($this->schemes[$scheme])) return $this->schemes[$scheme];
-        if (empty($this->_dir)) $this->_dir = HTMLPURIFIER_PREFIX . '/HTMLPurifier/URIScheme/';
-        
         if (!isset($allowed_schemes[$scheme])) return $null;
         
-        // this bit of reflection is not very efficient, and a bit
-        // hacky too
         $class = 'HTMLPurifier_URIScheme_' . $scheme;
-        if (!class_exists($class)) include_once $this->_dir . $scheme . '.php';
         if (!class_exists($class)) return $null;
         $this->schemes[$scheme] = new $class();
         return $this->schemes[$scheme];
     }
     
     /**
-     * Registers a custom scheme to the cache.
+     * Registers a custom scheme to the cache, bypassing reflection.
      * @param $scheme Scheme name
      * @param $scheme_obj HTMLPurifier_URIScheme object
      */
diff --git a/maintenance/merge-library.php b/maintenance/merge-library.php
index 4ee7d3f0..2d73824b 100755
--- a/maintenance/merge-library.php
+++ b/maintenance/merge-library.php
@@ -174,8 +174,9 @@ function copy_and_remove_includes($file, $sfile) {
  */
 function replace_includes_callback($matches) {
     $file = $matches[1];
-    // PHP 5 only file
-    if ($file == 'HTMLPurifier/Lexer/DOMLex.php' || $file == 'HTMLPurifier/Printer.php') {
+    // PHP 5 only file / PEAR files
+    $preserve = array('HTMLPurifier/Lexer/DOMLex.php'=>1, 'HTMLPurifier/Printer.php'=>1, 'XML/HTMLSax3.php'=>1);
+    if (isset($preserve[$file])) {
         return $matches[0];
     }
     if (isset($GLOBALS['loaded'][$file])) return '';
@@ -205,8 +206,8 @@ make_dir_standalone('HTMLPurifier/EntityLookup');
 make_dir_standalone('HTMLPurifier/Language');
 make_file_standalone('HTMLPurifier/Printer.php'); 
 make_dir_standalone('HTMLPurifier/Printer');
-make_dir_standalone('HTMLPurifier/URIScheme');
 make_dir_standalone('HTMLPurifier/Filter');
+make_file_standalone('HTMLPurifier/Lexer/PEARSax3.php'); // not incl by default
 // PHP 5 only files
 make_file_standalone('HTMLPurifier/Lexer/DOMLex.php');
 make_file_standalone('HTMLPurifier/Lexer/PH5P.php');