main.go | 2 +-

diff --git a/main.go b/main.go
index b5bd5f5069e49a0a58fed218635c418213efad05..23a3accbe2046619267e52bebb7c6d653e8b5934 100644
--- a/main.go
+++ b/main.go
@@ -134,7 +134,7 @@ 	ts := new(tai64n.TAI64N)
 	tai64n.FromTime(t, ts)
 	tai := ts.Encode()[1:]
 	fnOrig := p.FileName()
-	fd, err := os.OpenFile(tai+".part", os.O_WRONLY|os.O_CREATE, 0666)
+	fd, err := os.OpenFile(tai+".part", os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0666)
 	if err != nil {
 		log.Println(r.RemoteAddr, tai, fnOrig, err)
 		return