diff --git a/bt/announce.php b/bt/announce.php
index f9385012..7827e37a 100644
--- a/bt/announce.php
+++ b/bt/announce.php
@@ -102,6 +102,10 @@ if (!verify_id($passkey, BT_AUTH_KEY_LENGTH))
 {
 	msg_die('Invalid passkey: ' . $passkey);
 }
+if (max($uploaded, $downloaded, $left) >= (2**64 - 1)) // BIGINT
+{
+	msg_die('Integer overflow');
+}
 
 // Check for client ban
 if ($bb_cfg['client_ban']['enabled'])