diff --git a/tools/constants_test.go b/tools/constants_test.go
new file mode 100644
index 0000000..16cc81e
--- /dev/null
+++ b/tools/constants_test.go
@@ -0,0 +1,7 @@
+package tools_test
+
+// Using default softHSM configuration. Change it if necessary.
+const p11Lib = "/usr/lib/softhsm/libsofthsm2.so" // Path used by Ubuntu Bionic Beaver
+const p11Key = "1234"
+const p11LabelRSA = "test-hsm-rsa"
+const p11LabelECDSA = "test-hsm-ecdsa"
diff --git a/tools/context.go b/tools/context.go
index 9e0a806..aa4b145 100644
--- a/tools/context.go
+++ b/tools/context.go
@@ -51,7 +51,6 @@ func NewContext(config *ContextConfig, log *log.Logger) (ctx *Context, err error
 		Config:        config,
 		Log:           log,
 		SignAlgorithm: algorithm,
-		Glue:          make(map[string]struct{}),
 	}
 
 	if len(config.FilePath) > 0 {
@@ -89,6 +88,9 @@ func (ctx *Context) ReadAndParseZone(updateSerial bool) error {
 	if ctx.File == nil {
 		return fmt.Errorf("no file defined on context")
 	}
+	if ctx.Glue == nil {
+		ctx.Glue = make(map[string]struct{})
+	}
 
 	rrs := make(RRArray, 0)
 
diff --git a/tools/pkcs11_signer_test.go b/tools/pkcs11_signer_test.go
index 0d2f21a..f0b892d 100644
--- a/tools/pkcs11_signer_test.go
+++ b/tools/pkcs11_signer_test.go
@@ -9,12 +9,6 @@ import (
 	"github.com/niclabs/dns-tools/tools"
 )
 
-// Using default softHSM configuration. Change it if necessary.
-const p11Lib = "/usr/lib/softhsm/libsofthsm2.so" // Path used by Ubuntu Bionic Beaver
-const p11Key = "1234"
-const p11LabelRSA = "test-hsm-rsa"
-const p11LabelECDSA = "test-hsm-ecdsa"
-
 func TestSession_PKCS11RSASign(t *testing.T) {
 	ctx := &tools.Context{
 		Config: &tools.ContextConfig{
diff --git a/tools/rr_set.go b/tools/rr_set.go
index b93a943..b41ab51 100644
--- a/tools/rr_set.go
+++ b/tools/rr_set.go
@@ -286,12 +286,8 @@ func (ctx *Context) addNSEC3Records() error {
 		if typeMap[dns.TypeSOA] {
 			typeMap[dns.TypeNSEC3PARAM] = true
 		}
-		if !typeMap[dns.TypeDS] && !typeMap[dns.TypeDNSKEY] {
-			if ctx.Config.OptOut {
-				continue
-			} else {
-				ctx.Log.Printf("opt-out is not set and owner name %s has not a DS RR", rrSet[0].Header().Name)
-			}
+		if !typeMap[dns.TypeDS] && !typeMap[dns.TypeDNSKEY] && ctx.Config.OptOut {
+			continue
 		}
 		// Add current NSEC3 RR
 		err := nsec3list.add(rrSet[0].Header().Name, param, typeMap)