diff --git a/modules/dblog/dblog.install b/modules/dblog/dblog.install
index 5b5e6d092be03fe8d326f1118acf831593852c04..e5390396e8633a30f9f4e91bfbf3c5d0af8dc449 100644
--- a/modules/dblog/dblog.install
+++ b/modules/dblog/dblog.install
@@ -92,24 +92,6 @@ function dblog_schema() {
   return $schema;
 }
 
-/**
- * @defgroup updates-6.x-extra Extra database logging updates for 6.x
- * @{
- */
-
-/**
- * Allow longer referrers.
- */
-function dblog_update_6000() {
-  db_change_field('watchdog', 'referer', 'referer', array('type' => 'text', 'not null' => FALSE));
-}
-
-/**
- * @} End of "defgroup updates-6.x-extra"
- * The next series of updates should start at 7000.
- */
-
-
 /**
  * @defgroup updates-6.x-to-7.x database logging updates from 6.x to 7.x
  * @{
diff --git a/modules/statistics/statistics.install b/modules/statistics/statistics.install
index 38af02dbc159422d5b562bfbd955405133b194d2..a54a7ffdaadb0f1e3e3ead241e802363226eee96 100644
--- a/modules/statistics/statistics.install
+++ b/modules/statistics/statistics.install
@@ -133,24 +133,6 @@ function statistics_schema() {
   return $schema;
 }
 
-/**
- * @defgroup updates-6.x-extra Extra statistics updates for 6.x
- * @{
- */
-
-/**
- * Allow longer referrers.
- */
-function statistics_update_6000() {
-  db_change_field('accesslog', 'url', 'url', array('type' => 'text', 'not null' => FALSE));
-}
-
-/**
- * @} End of "defgroup updates-6.x-extra"
- * The next series of updates should start at 7000.
- */
-
-
 /**
  * @defgroup updates-6.x-to-7.x statistics updates from 6.x to 7.x
  * @{
diff --git a/modules/system/system.install b/modules/system/system.install
index a442b2f6a879e7c80b4fb90f7cef2a65022c54cc..d26a203f51da1f93a5c32990b13975fd08df1e2c 100644
--- a/modules/system/system.install
+++ b/modules/system/system.install
@@ -1513,107 +1513,9 @@ function system_schema() {
 // Updates for core.
 
 function system_update_last_removed() {
-  return 6047;
+  return 6055;
 }
 
-/**
- * @defgroup updates-6.x-extra Extra system updates for 6.x
- * @{
- */
-
-/**
-* Increase the size of the 'load_functions' and 'to_arg_functions' fields in table 'menu_router'.
-*/
-function system_update_6048() {
-  db_change_field('menu_router', 'load_functions', 'load_functions', array('type' => 'text', 'not null' => TRUE,));
-  db_change_field('menu_router', 'to_arg_functions', 'to_arg_functions', array('type' => 'text', 'not null' => TRUE,));
-}
-
-/**
- * Replace src index on the {url_alias} table with src, language.
- */
-function system_update_6049() {
-  db_drop_index('url_alias', 'src');
-  db_add_index('url_alias', 'src_language', array('src', 'language'));
-}
-
-/**
- * Clear any menu router blobs stored in the cache table.
- */
-function system_update_6050() {
-  cache_clear_all('router:', 'cache_menu', TRUE);
-}
-
-/**
- * Create a signature_format column.
- */
-function system_update_6051() {
-
-  if (!db_field_exists('users', 'signature_format')) {
-
-    // Set future text formats to FILTER_FORMAT_DEFAULT to ensure a safe default
-    // when incompatible modules insert into the users table. An actual format
-    // will be assigned when users save their signature.
-
-    $schema = array(
-      'type' => 'int',
-      'size' => 'small',
-      'not null' => TRUE,
-      'default' => FILTER_FORMAT_DEFAULT,
-      'description' => 'The {filter_formats}.format of the signature.',
-    );
-
-    db_add_field('users', 'signature_format', $schema);
-
-    // Set the format of existing signatures to the current default text format.
-    if ($current_default_filter = variable_get('filter_default_format', 0)) {
-      db_update('users')
-        ->fields(array(
-          'signature_format' => $current_default_filter,
-        ))
-        ->execute();
-    }
-
-    drupal_set_message("User signatures no longer inherit comment text formats. Each user's signature now has its own associated format that can be selected on the user's account page. Existing signatures have been set to your site's default text format.");
-  }
-}
-
-/**
- * Add a missing index on the {menu_router} table.
- */
-function system_update_6052() {
-  db_add_index('menu_router', 'tab_root_weight_title', array(array('tab_root', 64), 'weight', 'title'));
-}
-
-/**
- * Add a {system} index on type and name.
- */
-function system_update_6053() {
-  db_add_index('system', 'type_name', array(array('type', 12), 'name'));
-}
-
-/**
- * Improve indexes on the {url_alias} table.
- */
-function system_update_6055() {
-  db_drop_index('url_alias', 'src_language');
-  db_drop_unique_key('url_alias', 'dst_language');
-  db_add_index('url_alias', 'src_language_pid', array('src', 'language', 'pid'));
-  db_add_unique_key('url_alias', 'dst_language_pid', array('dst', 'language', 'pid'));
-}
-
-/**
- * Add semaphore table.
- */
-function system_update_6054() {
-  // Lives in update_fix_d7_requirements()
-}
-
-/**
- * @} End of "defgroup updates-6.x-extra"
- * The next series of updates should start at 7000.
- */
-
 /**
  * @defgroup updates-6.x-to-7.x System updates from 6.x to 7.x
  * @{