diff --git a/phpBB/includes/acp/acp_database.php b/phpBB/includes/acp/acp_database.php
index b98756a34b..fbc4f045ad 100644
--- a/phpBB/includes/acp/acp_database.php
+++ b/phpBB/includes/acp/acp_database.php
@@ -203,7 +203,7 @@ class acp_database
 						$file = $request->variable('file', '');
 						$download = $request->variable('download', '');
 
-						if (!preg_match('#^backup_\d{10,}_[a-z\d]{16}\.(sql(?:\.(?:gz|bz2))?)$#', $file, $matches))
+						if (!preg_match('#^backup_\d{10,}_[a-z\d]+\.(sql(?:\.(?:gz|bz2))?)$#i', $file, $matches))
 						{
 							trigger_error($user->lang['BACKUP_INVALID'] . adm_back_link($this->u_action), E_USER_WARNING);
 						}
@@ -402,7 +402,7 @@ class acp_database
 						{
 							while (($file = readdir($dh)) !== false)
 							{
-								if (preg_match('#^backup_(\d{10,})_[a-z\d]{16}\.(sql(?:\.(?:gz|bz2))?)$#', $file, $matches))
+								if (preg_match('#^backup_(\d{10,})_[a-z\d]+\.(sql(?:\.(?:gz|bz2))?)$#i', $file, $matches))
 								{
 									if (in_array($matches[2], $methods))
 									{
diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 3fec88a354..79d88fb3a5 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -115,7 +115,7 @@ function gen_rand_string_friendly($num_chars = 8)
 */
 function unique_id()
 {
-	return gen_rand_string(32);
+	return strtolower(gen_rand_string(32));
 }
 
 /**