diff --git a/msg_test.go b/msg_test.go
index 14e5f18..b86be9f 100644
--- a/msg_test.go
+++ b/msg_test.go
@@ -216,6 +216,9 @@ func (mw uppercaseMiddleware) Handle(m *Msg) *Msg {
 	if !ok {
 		fmt.Println("can't find the subject header")
 	}
+	if s == nil || len(s) < 1 {
+		s = append(s, "")
+	}
 	m.Subject(strings.ToUpper(s[0]))
 	return m
 }
@@ -231,6 +234,9 @@ func (mw encodeMiddleware) Handle(m *Msg) *Msg {
 	if !ok {
 		fmt.Println("can't find the subject header")
 	}
+	if s == nil || len(s) < 1 {
+		s = append(s, "")
+	}
 	m.Subject(strings.Replace(s[0], "a", "@", -1))
 	return m
 }