diff --git a/client_test.go b/client_test.go
index be81c0d6..03013506 100644
--- a/client_test.go
+++ b/client_test.go
@@ -19,34 +19,18 @@ func TestClientSync(t *testing.T) {
 	}
 }
 
-func helloMiek(w RequestWriter, r *Msg) {
-	w.Send(r)
-	reply, _ := w.Receive()
-	w.Write(reply)
-}
-
 func TestClientASync(t *testing.T) {
-	HandleQueryFunc("miek.nl.", helloMiek) // All queries for miek.nl will be handled by HelloMiek
-	ListenAndQuery(nil)                    // Detect if this isn't running
-
 	m := new(Msg)
 	m.SetQuestion("miek.nl.", TypeSOA)
 
 	c := new(Client)
-	c.Do(m, "85.223.71.124:53")
-
-forever:
-	for {
-		select {
-		case n := <-c.Reply:
-			if n.Reply != nil && n.Reply.Rcode != RcodeSuccess {
-				t.Log("Failed to get an valid answer")
-				t.Fail()
-				t.Logf("%v\n", n.Reply)
-			}
-			break forever
+	c.Do(m, "85.223.71.124:53", nil, func(m, r *Msg, e error, d interface{}) {
+		if r != nil && r.Rcode != RcodeSuccess {
+			t.Log("Failed to get an valid answer")
+			t.Fail()
+			t.Logf("%v\n", r)
 		}
-	}
+	})
 }
 
 func TestClientEDNS0(t *testing.T) {
diff --git a/defaults.go b/defaults.go
index 3064a7d2..ac4649ce 100644
--- a/defaults.go
+++ b/defaults.go
@@ -284,7 +284,7 @@ func IsDomainName(s string) (uint8, uint8, bool) { // copied from net package.
 // IsSubDomain checks if child is indeed a child of the parent.
 func IsSubDomain(parent, child string) bool {
 	// Entire child is contained in parent
-	return CompareLabels(child, parent) == LenLabels(child)
+	return CompareLabels(parent, child) == LenLabels(parent)
 }
 
 // IsFqdn checks if a domain name is fully qualified.
diff --git a/dns_test.go b/dns_test.go
index 430c1585..4463965a 100644
--- a/dns_test.go
+++ b/dns_test.go
@@ -75,6 +75,8 @@ func TestBailiwick(t *testing.T) {
 	for parent, child := range yes {
 		if !IsSubDomain(parent, child) {
 			t.Logf("%s should be child of %s\n", child, parent)
+			t.Logf("comparelabels %d", CompareLabels(parent, child))
+			t.Logf("lenlabels %d %d", LenLabels(parent), LenLabels(child))
 			t.Fail()
 		}
 	}
@@ -85,6 +87,8 @@ func TestBailiwick(t *testing.T) {
 	for parent, child := range no {
 		if IsSubDomain(parent, child) {
 			t.Logf("%s should not be child of %s\n", child, parent)
+			t.Logf("comparelabels %d", CompareLabels(parent, child))
+			t.Logf("lenlabels %d %d", LenLabels(parent), LenLabels(child))
 			t.Fail()
 		}
 	}