diff --git a/CHANGELOG b/CHANGELOG
index 5e870b0f7..c59d6cdbf 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Remove backward compatibility "layer" of bc.php (#4902)
 - Support WEBP images in mail messages (#5362)
 - Support MathML in HTML message preview (#5182)
 - Rename Addressbook to Contacts (#5233)
diff --git a/program/include/bc.php b/program/include/bc.php
deleted file mode 100644
index b4350e48e..000000000
--- a/program/include/bc.php
+++ /dev/null
@@ -1,512 +0,0 @@
-<?php
-
-/*
- +-----------------------------------------------------------------------+
- | program/include/bc.php                                                |
- |                                                                       |
- | This file is part of the Roundcube Webmail client                     |
- | Copyright (C) 2005-2012, The Roundcube Dev Team                       |
- |                                                                       |
- | Licensed under the GNU General Public License version 3 or            |
- | any later version with exceptions for skins & plugins.                |
- | See the README file for a full license statement.                     |
- |                                                                       |
- | PURPOSE:                                                              |
- |   Provide deprecated functions aliases for backward compatibility     |
- |                                                                       |
- +-----------------------------------------------------------------------+
- | Author: Thomas Bruederli <roundcube@gmail.com>                        |
- +-----------------------------------------------------------------------+
-*/
-
-/**
- * Roundcube Webmail deprecated functions
- *
- * @package Webmail
- * @subpackage Legacy
- * @author Thomas Bruederli <roundcube@gmail.com>
- */
-
-// constants for input reading
-define('RCUBE_INPUT_GET',  rcube_utils::INPUT_GET);
-define('RCUBE_INPUT_POST', rcube_utils::INPUT_POST);
-define('RCUBE_INPUT_GPC',  rcube_utils::INPUT_GPC);
-
-define('JS_OBJECT_NAME',   rcmail_output::JS_OBJECT_NAME);
-define('RCMAIL_CHARSET',   RCUBE_CHARSET);
-
-function get_table_name($table)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->db->table_name($table);
-}
-
-function rcube_label($p, $domain=null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->gettext($p, $domain);
-}
-
-function rcube_label_exists($name, $domain=null, &$ref_domain = null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->text_exists($name, $domain, $ref_domain);
-}
-
-function rcmail_overwrite_action($action)
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->overwrite_action($action);
-}
-
-function rcmail_url($action, $p=array(), $task=null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->url((array)$p + array('_action' => $action, 'task' => $task));
-}
-
-function rcmail_temp_gc()
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->gc_temp();
-}
-
-function rcube_charset_convert($str, $from, $to=NULL)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_charset::convert($str, $from, $to);
-}
-
-function rc_detect_encoding($string, $failover='')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_charset::detect($string, $failover);
-}
-
-function rc_utf8_clean($input)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_charset::clean($input);
-}
-
-function json_serialize($input)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_output::json_serialize($input);
-}
-
-function rep_specialchars_output($str, $enctype='', $mode='', $newlines=true)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::rep_specialchars_output($str, $enctype, $mode, $newlines);
-}
-
-function Q($str, $mode='strict', $newlines=true)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::rep_specialchars_output($str, 'html', $mode, $newlines);
-}
-
-function JQ($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::rep_specialchars_output($str, 'js');
-}
-
-function get_input_value($fname, $source, $allow_html=FALSE, $charset=NULL)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::get_input_value($fname, $source, $allow_html, $charset);
-}
-
-function parse_input_value($value, $allow_html=FALSE, $charset=NULL)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::parse_input_value($value, $allow_html, $charset);
-}
-
-function request2param($mode = RCUBE_INPUT_GPC, $ignore = 'task|action')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::request2param($mode, $ignore);
-}
-
-function html_identifier($str, $encode=false)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::html_identifier($str, $encode);
-}
-
-function rcube_table_output($attrib, $table_data, $a_show_cols, $id_col)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->table_output($attrib, $table_data, $a_show_cols, $id_col);
-}
-
-function rcmail_get_edit_field($col, $value, $attrib, $type='text')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_output::get_edit_field($col, $value, $attrib, $type);
-}
-
-function rcmail_mod_css_styles($source, $container_id, $allow_remote=false)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::mod_css_styles($source, $container_id, $allow_remote);
-}
-
-function rcmail_xss_entity_decode($content)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::xss_entity_decode($content);
-}
-
-function create_attrib_string($attrib, $allowed_attribs=array('id', 'class', 'style'))
-{
-    _deprecation_warning(__FUNCTION__);
-    return html::attrib_string($attrib, $allowed_attribs);
-}
-
-function parse_attrib_string($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return html::parse_attrib_string($str);
-}
-
-function format_date($date, $format=NULL, $convert=true)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->format_date($date, $format, $convert);
-}
-
-function rcmail_mailbox_list($attrib)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->folder_list($attrib);
-}
-
-function rcmail_mailbox_select($attrib = array())
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->folder_selector($attrib);
-}
-
-function rcmail_render_folder_tree_html(&$arrFolders, &$mbox_name, &$jslist, $attrib, $nestLevel = 0)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->render_folder_tree_html($arrFolders, $mbox_name, $jslist, $attrib, $nestLevel);
-}
-
-function rcmail_render_folder_tree_select(&$arrFolders, &$mbox_name, $maxlength, &$select, $realnames = false, $nestLevel = 0, $opts = array())
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->render_folder_tree_select($arrFolders, $mbox_name, $maxlength, $select, $realnames, $nestLevel, $opts);    
-}
-
-function rcmail_build_folder_tree(&$arrFolders, $folder, $delm = '/', $path = '')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->build_folder_tree($arrFolders, $folder, $delm, $path);
-}
-
-function rcmail_folder_classname($folder_id)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->folder_classname($folder_id);
-}
-
-function rcmail_localize_foldername($name)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->localize_foldername($name);
-}
-
-function rcmail_localize_folderpath($path)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->localize_folderpath($path);
-}
-
-function rcmail_quota_display($attrib)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->quota_display($attrib);
-}
-
-function rcmail_quota_content($attrib = null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->quota_content($attrib);
-}
-
-function rcmail_display_server_error($fallback=null, $fallback_args=null, $suffix='')
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->display_server_error($fallback, $fallback_args, $suffix);
-}
-
-function rcmail_filetype2classname($mimetype, $filename)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::file2class($mimetype, $filename);
-}
-
-function rcube_html_editor($mode='')
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->html_editor($mode);
-}
-
-function rcmail_replace_emoticons($html)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->replace_emoticons($html);
-}
-
-function rcmail_deliver_message(&$message, $from, $mailto, &$smtp_error, &$body_file=null, $smtp_opts=null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->deliver_message($message, $from, $mailto, $smtp_error, $body_file, $smtp_opts);
-}
-
-function rcmail_gen_message_id()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->gen_message_id();
-}
-
-function rcmail_user_date()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->user_date();
-}
-
-function rcmail_mem_check($need)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::mem_check($need);
-}
-
-function rcube_https_check($port=null, $use_https=true)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::https_check($port, $use_https);
-}
-
-function rcube_sess_unset($var_name=null)
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->session->remove($var_name);
-}
-
-function rcube_parse_host($name, $host='')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::parse_host($name, $host);
-}
-
-function check_email($email, $dns_check=true)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::check_email($email, $dns_check);
-}
-
-function console()
-{
-    _deprecation_warning(__FUNCTION__);
-    call_user_func_array(array('rcmail', 'console'), func_get_args());
-}
-
-function write_log($name, $line)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::write_log($name, $line);
-}
-
-function rcmail_log_login()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->log_login();
-}
-
-function rcmail_remote_ip()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::remote_ip();
-}
-
-function rcube_check_referer()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::check_referer();
-}
-
-function rcube_timer()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::timer();
-}
-
-function rcube_print_time($timer, $label='Timer', $dest='console')
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::print_timer($timer, $label, $dest);
-}
-
-function raise_error($arg=array(), $log=false, $terminate=false)
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::raise_error($arg, $log, $terminate);
-}
-
-function rcube_log_bug($arg_arr)
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::log_bug($arg_arr);
-}
-
-function rcube_upload_progress()
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->upload_progress();
-}
-
-function rcube_upload_init()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->upload_init();
-}
-
-function rcube_autocomplete_init()
-{
-    _deprecation_warning(__FUNCTION__);
-    rcmail::get_instance()->autocomplete_init();
-}
-
-function rcube_fontdefs($font = null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::font_defs($font);
-}
-
-function send_nocacheing_headers()
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->output->nocacheing_headers();
-}
-
-function show_bytes($bytes)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->show_bytes($bytes);
-}
-
-function rc_wordwrap($string, $width=75, $break="\n", $cut=false, $charset=null)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_mime::wordwrap($string, $width, $break, $cut, $charset);
-}
-
-function rc_request_header($name)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::request_header($name);
-}
-
-function rcube_explode_quoted_string($delimiter, $string)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::explode_quoted_string($delimiter, $string);
-}
-
-function rc_mime_content_type($path, $name, $failover = 'application/octet-stream', $is_stream=false)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_mime::file_content_type($path, $name, $failover, $is_stream);
-}
-
-function rc_image_content_type($data)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_mime::image_content_type($data);
-}
-
-function rcube_strtotime($date)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::strtotime($date);
-}
-
-function rcube_idn_to_ascii($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::idn_to_ascii($str);
-}
-
-function rcube_idn_to_utf8($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::idn_to_utf8($str);
-}
-
-function send_future_expire_header($offset = 2600000)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcmail::get_instance()->output->future_expire_header($offset);
-}
-
-function get_opt($aliases = array())
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::get_opt($aliases);
-}
-
-function prompt_silent($prompt = 'Password:')
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::prompt_silent($prompt);
-}
-
-function get_boolean($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_utils::get_boolean($str);
-}
-
-function enriched_to_html($data)
-{
-    _deprecation_warning(__FUNCTION__);
-    return rcube_enriched::to_html($data);
-}
-
-function strip_quotes($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return str_replace(array("'", '"'), '', $str);
-}
-
-function strip_newlines($str)
-{
-    _deprecation_warning(__FUNCTION__);
-    return preg_replace('/[\r\n]/', '', $str);
-}
-
-function _deprecation_warning($func)
-{
-    static $warnings = array();
-
-    if (!$warnings[$func]++)  // only log once
-        rcmail::write_log('errors', "Warning: Call to deprecated function $func(); See bc.inc for replacement");
-}
-
-class rcube_html_page extends rcmail_html_page
-{
-}
-
-class washtml extends rcube_washtml
-{
-}
-
-class html2text extends rcube_html2text
-{
-}
diff --git a/program/include/iniset.php b/program/include/iniset.php
index dfa6fe98a..dbe93b3e5 100644
--- a/program/include/iniset.php
+++ b/program/include/iniset.php
@@ -65,9 +65,6 @@ require_once 'Roundcube/bootstrap.php';
 // register autoloader for rcmail app classes
 spl_autoload_register('rcmail_autoload');
 
-// backward compatybility (to be removed in version 1.2.0)
-require_once INSTALL_PATH . 'program/include/bc.php';
-
 /**
  * PHP5 autoloader routine for dynamic class loading
  */