diff --git a/dns_test.go b/dns_test.go
index ac37d76b..f91b4597 100644
--- a/dns_test.go
+++ b/dns_test.go
@@ -316,6 +316,22 @@ func TestMsgLength2(t *testing.T) {
 	}
 }
 
+func testMsgLengthCompressionMalformed(t *testing.T) {
+	// SOA with empty hostmaster, which is illegal
+	soa := &SOA{Hdr: RR_Header{Name: ".", Rrtype: TypeSOA, Class: ClassINET, Ttl: 12345},
+        Ns:      ".",
+        Mbox:    "",
+        Serial:  0,
+        Refresh: 28800,
+        Retry:   7200,
+        Expire:  604800,
+        Minttl:  60}
+	m := new(Msg)
+	m.Compress = true
+	m.Ns = []RR{soa}
+	m.Len()
+}
+
 func BenchmarkMsgLength(b *testing.B) {
 	b.StopTimer()
 	makeMsg := func(question string, ans, ns, e []RR) *Msg {