Index: wp-admin/includes/upgrade.php
===================================================================
--- wp-admin/includes/upgrade.php	(revision 17501)
+++ wp-admin/includes/upgrade.php	(working copy)
@@ -1831,10 +1831,12 @@
  * @since 2.1.0
  */
 function wp_check_mysql_version() {
-	global $wpdb;
-	$result = $wpdb->check_database_version();
-	if ( is_wp_error( $result ) )
+	global $wpdb, $wp_version, $required_mysql_version;
+	// Make sure the server has the required MySQL version
+	if ( version_compare($wpdb->db_version(), $required_mysql_version, '<') ) {
+		$result = new WP_Error('database_version', sprintf( __( '<strong>ERROR</strong>: WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version ));
 		die( $result->get_error_message() );
+	}
 }
 
 /**
Index: wp-includes/wp-db.php
===================================================================
--- wp-includes/wp-db.php	(revision 17501)
+++ wp-includes/wp-db.php	(working copy)
@@ -1486,22 +1486,6 @@
 	}
 
 	/**
-	 * Whether MySQL database is at least the required minimum version.
-	 *
-	 * @since 2.5.0
-	 * @uses $wp_version
-	 * @uses $required_mysql_version
-	 *
-	 * @return WP_Error
-	 */
-	function check_database_version() {
-		global $wp_version, $required_mysql_version;
-		// Make sure the server has the required MySQL version
-		if ( version_compare($this->db_version(), $required_mysql_version, '<') )
-			return new WP_Error('database_version', sprintf( __( '<strong>ERROR</strong>: WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version ));
-	}
-
-	/**
 	 * Whether the database supports collation.
 	 *
 	 * Called when WordPress is generating the table scheme.