diff --git a/src/pkg/crypto/tls/alert.go b/src/pkg/crypto/tls/alert.go
index 3b9e0e2415..0856311e4c 100644
--- a/src/pkg/crypto/tls/alert.go
+++ b/src/pkg/crypto/tls/alert.go
@@ -71,3 +71,7 @@ func (e alert) String() string {
 	}
 	return "alert(" + strconv.Itoa(int(e)) + ")"
 }
+
+func (e alert) Error() string {
+	return e.String()
+}