Index: wp-admin/includes/schema.php
===================================================================
--- wp-admin/includes/schema.php	(revision 30975)
+++ wp-admin/includes/schema.php	(working copy)
@@ -123,7 +123,7 @@
 ) $charset_collate;
 CREATE TABLE $wpdb->options (
   option_id bigint(20) unsigned NOT NULL auto_increment,
-  option_name varchar(64) NOT NULL default '',
+  option_name varchar(255) NOT NULL default '',
   option_value longtext NOT NULL,
   autoload varchar(20) NOT NULL default 'yes',
   PRIMARY KEY  (option_id),
Index: wp-admin/includes/upgrade.php
===================================================================
--- wp-admin/includes/upgrade.php	(revision 30975)
+++ wp-admin/includes/upgrade.php	(working copy)
@@ -442,6 +442,9 @@
 	if ( $wp_current_db_version < 29630 )
 		upgrade_400();
 
+	if ( $wp_current_db_version < 30975 )
+		upgrade_420();
+
 	maybe_disable_link_manager();
 
 	maybe_disable_automattic_widgets();
@@ -1329,6 +1332,21 @@
 }
 
 /**
+ * Execute changes made in WordPress 4.2.0.
+ * ALTER TABLE <table_name> MODIFY <col_name> VARCHAR(65536)
+ *
+ * @since 4.2.0
+ */
+function upgrade_420() {
+	global $wpdb;
+
+	$wpdb->hide_errors();
+	$wpdb->query("ALTER TABLE {$wpdb->options} MODIFY option_name VARCHAR(255)");
+	$wpdb->show_errors();
+	return true;
+}
+
+/**
  * Execute network level changes
  *
  * @since 3.0.0
Index: wp-includes/version.php
===================================================================
--- wp-includes/version.php	(revision 30975)
+++ wp-includes/version.php	(working copy)
@@ -11,7 +11,7 @@
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 30133;
+$wp_db_version = 30975;
 
 /**
  * Holds the TinyMCE version