diff --git a/nl/nl_linux.go b/nl/nl_linux.go
index 8dbd92b..16253e1 100644
--- a/nl/nl_linux.go
+++ b/nl/nl_linux.go
@@ -149,10 +149,12 @@ func (a *RtAttr) Serialize() []byte {
 	length := a.Len()
 	buf := make([]byte, rtaAlignOf(length))
 
+	next := 4
 	if a.Data != nil {
-		copy(buf[4:], a.Data)
-	} else {
-		next := 4
+		copy(buf[next:], a.Data)
+		next += rtaAlignOf(len(a.Data))
+	}
+	if len(a.children) > 0 {
 		for _, child := range a.children {
 			childBuf := child.Serialize()
 			copy(buf[next:], childBuf)