diff --git a/providers/dns/dynu/dynu.go b/providers/dns/dynu/dynu.go
index c2df9fb4..9a9e9858 100644
--- a/providers/dns/dynu/dynu.go
+++ b/providers/dns/dynu/dynu.go
@@ -97,8 +97,7 @@ func (d *DNSProvider) Timeout() (timeout, interval time.Duration) {
 func (d *DNSProvider) Present(domain, token, keyAuth string) error {
 	fqdn, value := dns01.GetRecord(domain, keyAuth)
 
-	// TODO(ldez) replace domain by FQDN to follow CNAME.
-	rootDomain, err := d.client.GetRootDomain(domain)
+	rootDomain, err := d.client.GetRootDomain(dns01.UnFqdn(fqdn))
 	if err != nil {
 		return fmt.Errorf("dynu: could not find root domain for %s: %w", domain, err)
 	}
@@ -115,7 +114,7 @@ func (d *DNSProvider) Present(domain, token, keyAuth string) error {
 		}
 	}
 
-	subDomain, err := dns01.ExtractSubDomain(fqdn, domain)
+	subDomain, err := dns01.ExtractSubDomain(fqdn, rootDomain.DomainName)
 	if err != nil {
 		return fmt.Errorf("dynu: %w", err)
 	}
@@ -142,8 +141,7 @@ func (d *DNSProvider) Present(domain, token, keyAuth string) error {
 func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
 	fqdn, value := dns01.GetRecord(domain, keyAuth)
 
-	// TODO(ldez) replace domain by FQDN to follow CNAME.
-	rootDomain, err := d.client.GetRootDomain(domain)
+	rootDomain, err := d.client.GetRootDomain(dns01.UnFqdn(fqdn))
 	if err != nil {
 		return fmt.Errorf("dynu: could not find root domain for %s: %w", domain, err)
 	}