diff --git a/lib/udp-tracker.js b/lib/udp-tracker.js
index 30d1e11..bbd5eb3 100644
--- a/lib/udp-tracker.js
+++ b/lib/udp-tracker.js
@@ -219,7 +219,7 @@ UDPTracker.prototype._request = function (opts) {
       toUInt64(opts.downloaded),
       opts.left != null ? toUInt64(opts.left) : new Buffer('FFFFFFFFFFFFFFFF', 'hex'),
       toUInt64(opts.uploaded),
-      common.toUInt32(common.EVENTS[opts.event]),
+      common.toUInt32(common.EVENTS[opts.event] || 0),
       common.toUInt32(0), // ip address (optional)
       common.toUInt32(0), // key (optional)
       common.toUInt32(opts.numwant),