diff --git a/sql/000_base_structure.sql b/sql/000_base_structure.sql
index 138db841..a7e80be2 100644
--- a/sql/000_base_structure.sql
+++ b/sql/000_base_structure.sql
@@ -30,7 +30,8 @@ CREATE TABLE IF NOT EXISTS `accounts` (
   `coin_address` varchar(255) DEFAULT NULL,
   PRIMARY KEY (`id`),
   UNIQUE KEY `username` (`username`),
-  UNIQUE KEY `email` (`email`)
+  UNIQUE KEY `email` (`email`),
+  UNIQUE KEY `coin_address` (`coin_address`)
 ) ENGINE=InnoDB  DEFAULT CHARSET=utf8;
 
 CREATE TABLE IF NOT EXISTS `blocks` (