diff --git a/database/database.xml b/database/database.xml
index 490bc5a..af15ad5 100644
--- a/database/database.xml
+++ b/database/database.xml
@@ -7,6 +7,9 @@
 
         <field name="maxHistoryLength" type="integer" default="20"/>
         <field name="recordHistory" type="boolean" default="true"/>
+        <index unique="true">
+            <indexfield name="owner"/>
+        </index>
     </object>
 
     <object name="IrcServerOptions">