bep40.go | 2 +-

diff --git a/bep40.go b/bep40.go
index 5930247f15d6116299f0051baed218115de3b589..fa696bdac57233917e868cc40e2664ebb00b09ac 100644
--- a/bep40.go
+++ b/bep40.go
@@ -74,7 +74,7 @@
 func bep40Priority(a, b ipPort) (peerPriority, error) {
 	bs, err := bep40PriorityBytes(a, b)
 	if err != nil {
-		return 0, nil
+		return 0, err
 	}
 	i := len(bs) / 2
 	_a, _b := bs[:i], bs[i:]