diff --git a/cmd/ctrld/dns.go b/cmd/ctrld/dns.go
index 6d42867..770a630 100644
--- a/cmd/ctrld/dns.go
+++ b/cmd/ctrld/dns.go
@@ -1,3 +1,4 @@
 package main
 
+//lint:ignore U1000 use in os_linux.go
 type getDNS func(iface string) []string
diff --git a/cmd/ctrld/dns_proxy.go b/cmd/ctrld/dns_proxy.go
index 6d190cd..bd5176b 100644
--- a/cmd/ctrld/dns_proxy.go
+++ b/cmd/ctrld/dns_proxy.go
@@ -282,11 +282,12 @@ func containRcode(rcodes []int, rcode int) bool {
 }
 
 func setCachedAnswerTTL(answer *dns.Msg, now, expiredTime time.Time) {
-	ttl := uint32(expiredTime.Sub(now).Seconds())
-	if ttl < 0 {
+	ttlSecs := expiredTime.Sub(now).Seconds()
+	if ttlSecs < 0 {
 		return
 	}
 
+	ttl := uint32(ttlSecs)
 	for _, rr := range answer.Answer {
 		rr.Header().Ttl = ttl
 	}
diff --git a/cmd/ctrld/net.go b/cmd/ctrld/net.go
index 665759b..f98feb9 100644
--- a/cmd/ctrld/net.go
+++ b/cmd/ctrld/net.go
@@ -34,6 +34,8 @@ func supportsIPv6ListenLocal() bool {
 }
 
 // isIPv6 checks if the provided IP is v6.
+//
+//lint:ignore U1000 use in os_windows.go
 func isIPv6(ip string) bool {
 	parsedIP := net.ParseIP(ip)
 	return parsedIP != nil && parsedIP.To4() == nil && parsedIP.To16() != nil
diff --git a/resolver.go b/resolver.go
index af153d1..5c04f37 100644
--- a/resolver.go
+++ b/resolver.go
@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"net"
-	"strings"
 	"sync/atomic"
 
 	"github.com/miekg/dns"
@@ -96,13 +95,3 @@ func (r *legacyResolver) Resolve(ctx context.Context, msg *dns.Msg) (*dns.Msg, e
 	answer, _, err := dnsClient.ExchangeContext(ctx, msg, r.endpoint)
 	return answer, err
 }
-
-// canonicalName returns canonical name from FQDN with "." trimmed.
-func canonicalName(fqdn string) string {
-	q := strings.TrimSpace(fqdn)
-	q = strings.TrimSuffix(q, ".")
-	// https://datatracker.ietf.org/doc/html/rfc4343
-	q = strings.ToLower(q)
-
-	return q
-}