diff --git a/kill.go b/kill.go
index 78e4c18a1..476ea95d7 100644
--- a/kill.go
+++ b/kill.go
@@ -93,13 +93,7 @@ signal to the init process of the "ubuntu01" container:
 func parseSignal(rawSignal string) (syscall.Signal, error) {
 	s, err := strconv.Atoi(rawSignal)
 	if err == nil {
-		sig := syscall.Signal(s)
-		for _, msig := range signalMap {
-			if sig == msig {
-				return sig, nil
-			}
-		}
-		return -1, fmt.Errorf("unknown signal %q", rawSignal)
+		return syscall.Signal(s), nil
 	}
 	signal, ok := signalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")]
 	if !ok {