diff --git a/app/dns/nameserver_doh.go b/app/dns/nameserver_doh.go
index db61e831a40..88350f2ee11 100644
--- a/app/dns/nameserver_doh.go
+++ b/app/dns/nameserver_doh.go
@@ -304,11 +304,11 @@ func (s *DoHNameServer) findIPsForDomain(domain string, option dns_feature.IPOpt
 	var ips []net.Address
 	var ip6 []net.Address
 
-	if option.IPv4Enable {
+	switch {
+	case option.IPv4Enable:
 		ips, err4 = record.A.getIPs()
-	}
-
-	if option.IPv6Enable {
+		fallthrough
+	case option.IPv6Enable:
 		ip6, err6 = record.AAAA.getIPs()
 		ips = append(ips, ip6...)
 	}
diff --git a/app/dns/nameserver_quic.go b/app/dns/nameserver_quic.go
index b0618ecee40..f2e2573edfa 100644
--- a/app/dns/nameserver_quic.go
+++ b/app/dns/nameserver_quic.go
@@ -241,11 +241,11 @@ func (s *QUICNameServer) findIPsForDomain(domain string, option dns_feature.IPOp
 	var ips []net.Address
 	var ip6 []net.Address
 
-	if option.IPv4Enable {
+	switch {
+	case option.IPv4Enable:
 		ips, err4 = record.A.getIPs()
-	}
-
-	if option.IPv6Enable {
+		fallthrough
+	case option.IPv6Enable:
 		ip6, err6 = record.AAAA.getIPs()
 		ips = append(ips, ip6...)
 	}
diff --git a/app/dns/nameserver_tcp.go b/app/dns/nameserver_tcp.go
index c114d6152f0..be51ffb57c8 100644
--- a/app/dns/nameserver_tcp.go
+++ b/app/dns/nameserver_tcp.go
@@ -283,11 +283,11 @@ func (s *TCPNameServer) findIPsForDomain(domain string, option dns_feature.IPOpt
 	var ips []net.Address
 	var ip6 []net.Address
 
-	if option.IPv4Enable {
+	switch {
+	case option.IPv4Enable:
 		ips, err4 = record.A.getIPs()
-	}
-
-	if option.IPv6Enable {
+		fallthrough
+	case option.IPv6Enable:
 		ip6, err6 = record.AAAA.getIPs()
 		ips = append(ips, ip6...)
 	}
diff --git a/app/dns/nameserver_udp.go b/app/dns/nameserver_udp.go
index 70c8beab48c..5d88da148e3 100644
--- a/app/dns/nameserver_udp.go
+++ b/app/dns/nameserver_udp.go
@@ -223,11 +223,11 @@ func (s *ClassicNameServer) findIPsForDomain(domain string, option dns_feature.I
 	var ips []net.Address
 	var ip6 []net.Address
 
-	if option.IPv4Enable {
+	switch {
+	case option.IPv4Enable:
 		ips, err4 = record.A.getIPs()
-	}
-
-	if option.IPv6Enable {
+		fallthrough
+	case option.IPv6Enable:
 		ip6, err6 = record.AAAA.getIPs()
 		ips = append(ips, ip6...)
 	}