diff --git a/system/dbupdate_3.4/13011_installation_on_multiple_servers.php b/system/dbupdate_3.4/13011_installation_on_multiple_servers.php
new file mode 100644
index 000000000..24c496457
--- /dev/null
+++ b/system/dbupdate_3.4/13011_installation_on_multiple_servers.php
@@ -0,0 +1,36 @@
+<?php
+
+if (! defined('DB_NAME')) exit('No direct script access allowed');
+
+// stud_selfservice boolean fuer public.tbl_vorlage
+if(!@$db->db_query("SELECT server_kurzbz FROM system.tbl_extensions LIMIT 1"))
+{
+	$qry = "ALTER TABLE system.tbl_extensions ADD COLUMN server_kurzbz varchar(64);
+			ALTER TABLE system.tbl_extensions ADD CONSTRAINT fk_extensios_server_kurzbz FOREIGN KEY (server_kurzbz) REFERENCES system.tbl_server(server_kurzbz) ON UPDATE CASCADE ON DELETE RESTRICT;";
+
+	if(!$db->db_query($qry))
+		echo '<strong>App: '.$db->db_last_error().'</strong><br>';
+	else
+		echo '<br>Neue Spalte server_kurzbz in system.tbl_extensions hinzugefügt';
+}
+
+
+// UNIQUE INDEX uidx_extensions_name_version_server
+if ($result = $db->db_query("SELECT 0 FROM pg_class WHERE relname = 'uidx_extensions_name_version_server'"))
+{
+	if ($db->db_num_rows($result) == 1)
+	{
+		$qry = 'DROP INDEX system.uidx_extensions_name_version';
+		if (!$db->db_query($qry))
+			echo '<strong>uidx_extensions_name_version_server '.$db->db_last_error().'</strong><br>';
+		else
+			echo '<br>Dropped unique uidx_extensions_name_version_server';
+	}
+
+	$qry = 'CREATE UNIQUE INDEX uidx_extensions_name_version_server ON system.tbl_extensions USING btree (name, version, server_kurzbz);';
+	if (!$db->db_query($qry))
+		echo '<strong>uidx_extensions_name_version_server '.$db->db_last_error().'</strong><br>';
+	else
+		echo '<br>Created unique uidx_extensions_name_version_server';
+}
+