Index: src/wp-includes/default-constants.php
===================================================================
--- src/wp-includes/default-constants.php	(revision 41199)
+++ src/wp-includes/default-constants.php	(working copy)
@@ -80,6 +80,10 @@
 	if ( !defined('WP_CACHE') )
 		define('WP_CACHE', false);
 
+	if ( ! defined( 'WP_DISABLE_DEPRECATED' ) ) {
+		define( 'WP_DISABLE_DEPRECATED', false );
+	}
+
 	// Add define('SCRIPT_DEBUG', true); to wp-config.php to enable loading of non-minified,
 	// non-concatenated scripts and stylesheets.
 	if ( ! defined( 'SCRIPT_DEBUG' ) ) {
Index: src/wp-settings.php
===================================================================
--- src/wp-settings.php	(revision 41199)
+++ src/wp-settings.php	(working copy)
@@ -188,7 +188,9 @@
 require( ABSPATH . WPINC . '/bookmark-template.php' );
 require( ABSPATH . WPINC . '/kses.php' );
 require( ABSPATH . WPINC . '/cron.php' );
-require( ABSPATH . WPINC . '/deprecated.php' );
+if ( WP_DISABLE_DEPRECATED ) {
+	require( ABSPATH . WPINC . '/deprecated.php' );
+}
 require( ABSPATH . WPINC . '/script-loader.php' );
 require( ABSPATH . WPINC . '/taxonomy.php' );
 require( ABSPATH . WPINC . '/class-wp-taxonomy.php' );
@@ -246,7 +248,9 @@
 if ( is_multisite() ) {
 	require( ABSPATH . WPINC . '/ms-functions.php' );
 	require( ABSPATH . WPINC . '/ms-default-filters.php' );
-	require( ABSPATH . WPINC . '/ms-deprecated.php' );
+	if ( WP_DISABLE_DEPRECATED ) {
+		require( ABSPATH . WPINC . '/ms-deprecated.php' );
+	}
 }
 
 // Define constants that rely on the API to obtain the default value.
@@ -306,7 +310,10 @@
 
 // Load pluggable functions.
 require( ABSPATH . WPINC . '/pluggable.php' );
-require( ABSPATH . WPINC . '/pluggable-deprecated.php' );
+
+if ( WP_DISABLE_DEPRECATED ) {
+	require( ABSPATH . WPINC . '/pluggable-deprecated.php' );
+}
 
 // Set internal encoding.
 wp_set_internal_encoding();