diff --git a/go.mod b/go.mod
index a46adc4a..708ff7f0 100644
--- a/go.mod
+++ b/go.mod
@@ -3,8 +3,9 @@ module github.com/AdguardTeam/AdGuardHome
 go 1.21.8
 
 require (
-	github.com/AdguardTeam/dnsproxy v0.66.0
-	github.com/AdguardTeam/golibs v0.20.2
+	// TODO(a.garipov): !! Use a tag when available.
+	github.com/AdguardTeam/dnsproxy v0.66.1-0.20240327142957-feea26e21b31
+	github.com/AdguardTeam/golibs v0.21.0
 	github.com/AdguardTeam/urlfilter v0.18.0
 	github.com/NYTimes/gziphandler v1.1.1
 	github.com/ameshkov/dnscrypt/v2 v2.2.7
diff --git a/go.sum b/go.sum
index 78696a26..c129ffce 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,7 @@
-github.com/AdguardTeam/dnsproxy v0.66.0 h1:RyUbyDxRSXBFjVG1l2/4HV3I98DtfIgpnZkgXkgHKnc=
-github.com/AdguardTeam/dnsproxy v0.66.0/go.mod h1:ZThEXbMUlP1RxfwtNW30ItPAHE6OF4YFygK8qjU/cvY=
-github.com/AdguardTeam/golibs v0.20.2 h1:9gThBFyuELf2ohRnUNeQGQsVBYI7YslaRLUFwVaUj8E=
-github.com/AdguardTeam/golibs v0.20.2/go.mod h1:/votX6WK1PdcZ3T2kBOPjPCGmfhlKixhI6ljYrFRPvI=
+github.com/AdguardTeam/dnsproxy v0.66.1-0.20240327142957-feea26e21b31 h1:t2bm38YS6iudsgmun/ThcPg/6hHc2/0aXOgiKwMPskw=
+github.com/AdguardTeam/dnsproxy v0.66.1-0.20240327142957-feea26e21b31/go.mod h1:XLfD6IpSplUZZ+f5vhWSJW1mp4wm+KkHWiMo9w7U1Ls=
+github.com/AdguardTeam/golibs v0.21.0 h1:0swWyNaHTmT7aMwffKd9d54g4wBd8Oaj0fl+5l/PRdE=
+github.com/AdguardTeam/golibs v0.21.0/go.mod h1:/votX6WK1PdcZ3T2kBOPjPCGmfhlKixhI6ljYrFRPvI=
 github.com/AdguardTeam/urlfilter v0.18.0 h1:ZZzwODC/ADpjJSODxySrrUnt/fvOCfGFaCW6j+wsGfQ=
 github.com/AdguardTeam/urlfilter v0.18.0/go.mod h1:IXxBwedLiZA2viyHkaFxY/8mjub0li2PXRg8a3d9Z1s=
 github.com/NYTimes/gziphandler v1.1.1 h1:ZUDjpQae29j0ryrS0u/B8HZfJBtBQHjqw2rQ2cqUQ3I=
diff --git a/internal/aghnet/addr.go b/internal/aghnet/addr.go
index e3013125..fa0bcf9c 100644
--- a/internal/aghnet/addr.go
+++ b/internal/aghnet/addr.go
@@ -1,10 +1,7 @@
 package aghnet
 
 import (
-	"fmt"
 	"strings"
-
-	"github.com/AdguardTeam/golibs/stringutil"
 )
 
 // NormalizeDomain returns a lowercased version of host without the final dot,
@@ -19,25 +16,3 @@ func NormalizeDomain(host string) (norm string) {
 
 	return strings.ToLower(strings.TrimSuffix(host, "."))
 }
-
-// NewDomainNameSet returns nil and error, if list has duplicate or empty domain
-// name.  Otherwise returns a set, which contains domain names normalized using
-// [NormalizeDomain].
-func NewDomainNameSet(list []string) (set *stringutil.Set, err error) {
-	set = stringutil.NewSet()
-
-	for i, host := range list {
-		if host == "" {
-			return nil, fmt.Errorf("at index %d: hostname is empty", i)
-		}
-
-		host = NormalizeDomain(host)
-		if set.Has(host) {
-			return nil, fmt.Errorf("duplicate hostname %q at index %d", host, i)
-		}
-
-		set.Add(host)
-	}
-
-	return set, nil
-}
diff --git a/internal/aghnet/addr_test.go b/internal/aghnet/addr_test.go
deleted file mode 100644
index 2bb30e31..00000000
--- a/internal/aghnet/addr_test.go
+++ /dev/null
@@ -1,59 +0,0 @@
-package aghnet_test
-
-import (
-	"testing"
-
-	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
-	"github.com/AdguardTeam/golibs/testutil"
-	"github.com/stretchr/testify/assert"
-)
-
-func TestNewDomainNameSet(t *testing.T) {
-	t.Parallel()
-
-	testCases := []struct {
-		name       string
-		wantErrMsg string
-		in         []string
-	}{{
-		name:       "nil",
-		wantErrMsg: "",
-		in:         nil,
-	}, {
-		name:       "success",
-		wantErrMsg: "",
-		in: []string{
-			"Domain.Example",
-			".",
-		},
-	}, {
-		name:       "dups",
-		wantErrMsg: `duplicate hostname "domain.example" at index 1`,
-		in: []string{
-			"Domain.Example",
-			"domain.example",
-		},
-	}, {
-		name:       "bad_domain",
-		wantErrMsg: "at index 0: hostname is empty",
-		in: []string{
-			"",
-		},
-	}}
-
-	for _, tc := range testCases {
-		tc := tc
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-			set, err := aghnet.NewDomainNameSet(tc.in)
-			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
-			if err != nil {
-				return
-			}
-
-			for _, host := range tc.in {
-				assert.Truef(t, set.Has(aghnet.NormalizeDomain(host)), "%q not matched", host)
-			}
-		})
-	}
-}
diff --git a/internal/aghos/filewalker.go b/internal/aghos/filewalker.go
index 97f966af..30c2d718 100644
--- a/internal/aghos/filewalker.go
+++ b/internal/aghos/filewalker.go
@@ -5,8 +5,8 @@ import (
 	"io"
 	"io/fs"
 
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
-	"github.com/AdguardTeam/golibs/stringutil"
 )
 
 // FileWalker is the signature of a function called for files in the file tree.
@@ -56,7 +56,7 @@ func checkFile(
 // srcSet.  srcSet must be non-nil.
 func handlePatterns(
 	fsys fs.FS,
-	srcSet *stringutil.Set,
+	srcSet *container.MapSet[string],
 	patterns ...string,
 ) (sub []string, err error) {
 	sub = make([]string, 0, len(patterns))
@@ -87,7 +87,7 @@ func handlePatterns(
 func (fw FileWalker) Walk(fsys fs.FS, initial ...string) (ok bool, err error) {
 	// The slice of sources keeps the order in which the files are walked since
 	// srcSet.Values() returns strings in undefined order.
-	srcSet := stringutil.NewSet()
+	srcSet := container.NewMapSet[string]()
 	var src []string
 	src, err = handlePatterns(fsys, srcSet, initial...)
 	if err != nil {
diff --git a/internal/aghos/fswatcher.go b/internal/aghos/fswatcher.go
index ff40ed64..9f3a6570 100644
--- a/internal/aghos/fswatcher.go
+++ b/internal/aghos/fswatcher.go
@@ -6,10 +6,10 @@ import (
 	"io/fs"
 	"path/filepath"
 
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/osutil"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/fsnotify/fsnotify"
 )
 
@@ -46,7 +46,7 @@ type osWatcher struct {
 	events chan event
 
 	// files is the set of tracked files.
-	files *stringutil.Set
+	files *container.MapSet[string]
 }
 
 // osWatcherPref is a prefix for logging and wrapping errors in osWathcer's
@@ -67,7 +67,7 @@ func NewOSWritesWatcher() (w FSWatcher, err error) {
 	return &osWatcher{
 		watcher: watcher,
 		events:  make(chan event, 1),
-		files:   stringutil.NewSet(),
+		files:   container.NewMapSet[string](),
 	}, nil
 }
 
diff --git a/internal/client/persistent.go b/internal/client/persistent.go
index d70966d7..06e346f4 100644
--- a/internal/client/persistent.go
+++ b/internal/client/persistent.go
@@ -12,10 +12,10 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering/safesearch"
 	"github.com/AdguardTeam/dnsproxy/proxy"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/google/uuid"
 )
 
@@ -98,7 +98,7 @@ type Persistent struct {
 }
 
 // SetTags sets the tags if they are known, otherwise logs an unknown tag.
-func (c *Persistent) SetTags(tags []string, known *stringutil.Set) {
+func (c *Persistent) SetTags(tags []string, known *container.MapSet[string]) {
 	for _, t := range tags {
 		if !known.Has(t) {
 			log.Info("skipping unknown tag %q", t)
diff --git a/internal/dnsforward/access.go b/internal/dnsforward/access.go
index 21b4a758..9f00dcd3 100644
--- a/internal/dnsforward/access.go
+++ b/internal/dnsforward/access.go
@@ -5,10 +5,12 @@ import (
 	"fmt"
 	"net/http"
 	"net/netip"
+	"slices"
 	"strings"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghalg"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/urlfilter"
@@ -16,17 +18,14 @@ import (
 	"github.com/AdguardTeam/urlfilter/rules"
 )
 
-// unit is a convenient alias for struct{}
-type unit = struct{}
-
 // accessManager controls IP and client blocking that takes place before all
 // other processing.  An accessManager is safe for concurrent use.
 type accessManager struct {
-	allowedIPs map[netip.Addr]unit
-	blockedIPs map[netip.Addr]unit
+	allowedIPs *container.MapSet[netip.Addr]
+	blockedIPs *container.MapSet[netip.Addr]
 
-	allowedClientIDs *stringutil.Set
-	blockedClientIDs *stringutil.Set
+	allowedClientIDs *container.MapSet[string]
+	blockedClientIDs *container.MapSet[string]
 
 	// TODO(s.chzhen):  Use [aghnet.IgnoreEngine].
 	blockedHostsEng *urlfilter.DNSEngine
@@ -40,15 +39,15 @@ type accessManager struct {
 // which may be an IP address, a CIDR, or a ClientID.
 func processAccessClients(
 	clientStrs []string,
-	ips map[netip.Addr]unit,
+	ips *container.MapSet[netip.Addr],
 	nets *[]netip.Prefix,
-	clientIDs *stringutil.Set,
+	clientIDs *container.MapSet[string],
 ) (err error) {
 	for i, s := range clientStrs {
 		var ip netip.Addr
 		var ipnet netip.Prefix
 		if ip, err = netip.ParseAddr(s); err == nil {
-			ips[ip] = unit{}
+			ips.Add(ip)
 		} else if ipnet, err = netip.ParsePrefix(s); err == nil {
 			*nets = append(*nets, ipnet)
 		} else {
@@ -67,11 +66,11 @@ func processAccessClients(
 // newAccessCtx creates a new accessCtx.
 func newAccessCtx(allowed, blocked, blockedHosts []string) (a *accessManager, err error) {
 	a = &accessManager{
-		allowedIPs: map[netip.Addr]unit{},
-		blockedIPs: map[netip.Addr]unit{},
+		allowedIPs: container.NewMapSet[netip.Addr](),
+		blockedIPs: container.NewMapSet[netip.Addr](),
 
-		allowedClientIDs: stringutil.NewSet(),
-		blockedClientIDs: stringutil.NewSet(),
+		allowedClientIDs: container.NewMapSet[string](),
+		blockedClientIDs: container.NewMapSet[string](),
 	}
 
 	err = processAccessClients(allowed, a.allowedIPs, &a.allowedNets, a.allowedClientIDs)
@@ -109,7 +108,7 @@ func newAccessCtx(allowed, blocked, blockedHosts []string) (a *accessManager, er
 
 // allowlistMode returns true if this *accessCtx is in the allowlist mode.
 func (a *accessManager) allowlistMode() (ok bool) {
-	return len(a.allowedIPs) != 0 || a.allowedClientIDs.Len() != 0 || len(a.allowedNets) != 0
+	return a.allowedIPs.Len() != 0 || a.allowedClientIDs.Len() != 0 || len(a.allowedNets) != 0
 }
 
 // isBlockedClientID returns true if the ClientID should be blocked.
@@ -152,7 +151,7 @@ func (a *accessManager) isBlockedIP(ip netip.Addr) (blocked bool, rule string) {
 		ipnets = a.allowedNets
 	}
 
-	if _, ok := ips[ip]; ok {
+	if ips.Has(ip) {
 		return blocked, ip.String()
 	}
 
@@ -176,9 +175,9 @@ func (s *Server) accessListJSON() (j accessListJSON) {
 	defer s.serverLock.RUnlock()
 
 	return accessListJSON{
-		AllowedClients:    stringutil.CloneSlice(s.conf.AllowedClients),
-		DisallowedClients: stringutil.CloneSlice(s.conf.DisallowedClients),
-		BlockedHosts:      stringutil.CloneSlice(s.conf.BlockedHosts),
+		AllowedClients:    slices.Clone(s.conf.AllowedClients),
+		DisallowedClients: slices.Clone(s.conf.DisallowedClients),
+		BlockedHosts:      slices.Clone(s.conf.BlockedHosts),
 	}
 }
 
diff --git a/internal/dnsforward/config.go b/internal/dnsforward/config.go
index cc75cdf7..9584b9ba 100644
--- a/internal/dnsforward/config.go
+++ b/internal/dnsforward/config.go
@@ -19,6 +19,7 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/dnsproxy/upstream"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
@@ -461,26 +462,29 @@ func (s *Server) prepareIpsetListSettings() (err error) {
 // unspecPorts if its address is unspecified.
 func collectListenAddr(
 	addrPort netip.AddrPort,
-	addrs map[netip.AddrPort]unit,
-	unspecPorts map[uint16]unit,
+	addrs *container.MapSet[netip.AddrPort],
+	unspecPorts *container.MapSet[uint16],
 ) {
 	if addrPort == (netip.AddrPort{}) {
 		return
 	}
 
-	addrs[addrPort] = unit{}
+	addrs.Add(addrPort)
 	if addrPort.Addr().IsUnspecified() {
-		unspecPorts[addrPort.Port()] = unit{}
+		unspecPorts.Add(addrPort.Port())
 	}
 }
 
 // collectDNSAddrs returns configured set of listening addresses.  It also
 // returns a set of ports of each unspecified listening address.
-func (conf *ServerConfig) collectDNSAddrs() (addrs mapAddrPortSet, unspecPorts map[uint16]unit) {
+func (conf *ServerConfig) collectDNSAddrs() (
+	addrs *container.MapSet[netip.AddrPort],
+	unspecPorts *container.MapSet[uint16],
+) {
 	// TODO(e.burkov):  Perhaps, we shouldn't allocate as much memory, since the
 	// TCP and UDP listening addresses are currently the same.
-	addrs = make(map[netip.AddrPort]unit, len(conf.TCPListenAddrs)+len(conf.UDPListenAddrs))
-	unspecPorts = map[uint16]unit{}
+	addrs = container.NewMapSet[netip.AddrPort]()
+	unspecPorts = container.NewMapSet[uint16]()
 
 	for _, laddr := range conf.TCPListenAddrs {
 		collectListenAddr(laddr.AddrPort(), addrs, unspecPorts)
@@ -511,25 +515,11 @@ type emptyAddrPortSet struct{}
 // Has implements the [addrPortSet] interface for [emptyAddrPortSet].
 func (emptyAddrPortSet) Has(_ netip.AddrPort) (ok bool) { return false }
 
-// mapAddrPortSet is the [addrPortSet] containing values of [netip.AddrPort] as
-// keys of a map.
-type mapAddrPortSet map[netip.AddrPort]unit
-
-// type check
-var _ addrPortSet = mapAddrPortSet{}
-
-// Has implements the [addrPortSet] interface for [mapAddrPortSet].
-func (m mapAddrPortSet) Has(addrPort netip.AddrPort) (ok bool) {
-	_, ok = m[addrPort]
-
-	return ok
-}
-
 // combinedAddrPortSet is the [addrPortSet] defined by some IP addresses along
 // with ports, any combination of which is considered being in the set.
 type combinedAddrPortSet struct {
-	// TODO(e.burkov):  Use sorted slices in combination with binary search.
-	ports map[uint16]unit
+	// TODO(e.burkov):  Use container.SliceSet when available.
+	ports *container.MapSet[uint16]
 	addrs []netip.Addr
 }
 
@@ -538,9 +528,7 @@ var _ addrPortSet = (*combinedAddrPortSet)(nil)
 
 // Has implements the [addrPortSet] interface for [*combinedAddrPortSet].
 func (m *combinedAddrPortSet) Has(addrPort netip.AddrPort) (ok bool) {
-	_, ok = m.ports[addrPort.Port()]
-
-	return ok && slices.Contains(m.addrs, addrPort.Addr())
+	return m.ports.Has(addrPort.Port()) && slices.Contains(m.addrs, addrPort.Addr())
 }
 
 // filterOut filters out all the upstreams that match um.  It returns all the
@@ -578,11 +566,11 @@ func filterOutAddrs(upsConf *proxy.UpstreamConfig, set addrPortSet) (err error)
 func (conf *ServerConfig) ourAddrsSet() (m addrPortSet, err error) {
 	addrs, unspecPorts := conf.collectDNSAddrs()
 	switch {
-	case len(addrs) == 0:
+	case addrs.Len() == 0:
 		log.Debug("dnsforward: no listen addresses")
 
 		return emptyAddrPortSet{}, nil
-	case len(unspecPorts) == 0:
+	case unspecPorts.Len() == 0:
 		log.Debug("dnsforward: filtering out addresses %s", addrs)
 
 		return addrs, nil
diff --git a/internal/dnsforward/dnsforward.go b/internal/dnsforward/dnsforward.go
index 5c99e0ed..a1d1eede 100644
--- a/internal/dnsforward/dnsforward.go
+++ b/internal/dnsforward/dnsforward.go
@@ -308,13 +308,13 @@ func (s *Server) WriteDiskConfig(c *Config) {
 	sc := s.conf.Config
 	*c = sc
 	c.RatelimitWhitelist = slices.Clone(sc.RatelimitWhitelist)
-	c.BootstrapDNS = stringutil.CloneSlice(sc.BootstrapDNS)
-	c.FallbackDNS = stringutil.CloneSlice(sc.FallbackDNS)
-	c.AllowedClients = stringutil.CloneSlice(sc.AllowedClients)
-	c.DisallowedClients = stringutil.CloneSlice(sc.DisallowedClients)
-	c.BlockedHosts = stringutil.CloneSlice(sc.BlockedHosts)
+	c.BootstrapDNS = slices.Clone(sc.BootstrapDNS)
+	c.FallbackDNS = slices.Clone(sc.FallbackDNS)
+	c.AllowedClients = slices.Clone(sc.AllowedClients)
+	c.DisallowedClients = slices.Clone(sc.DisallowedClients)
+	c.BlockedHosts = slices.Clone(sc.BlockedHosts)
 	c.TrustedProxies = slices.Clone(sc.TrustedProxies)
-	c.UpstreamDNS = stringutil.CloneSlice(sc.UpstreamDNS)
+	c.UpstreamDNS = slices.Clone(sc.UpstreamDNS)
 }
 
 // LocalPTRResolvers returns the current local PTR resolver configuration.
@@ -322,7 +322,7 @@ func (s *Server) LocalPTRResolvers() (localPTRResolvers []string) {
 	s.serverLock.RLock()
 	defer s.serverLock.RUnlock()
 
-	return stringutil.CloneSlice(s.conf.LocalPTRResolvers)
+	return slices.Clone(s.conf.LocalPTRResolvers)
 }
 
 // AddrProcConfig returns the current address processing configuration.  Only
diff --git a/internal/filtering/filter.go b/internal/filtering/filter.go
index e134175b..15bc14d9 100644
--- a/internal/filtering/filter.go
+++ b/internal/filtering/filter.go
@@ -13,9 +13,9 @@ import (
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghrenameio"
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/AdguardTeam/golibs/stringutil"
 )
 
 // filterDir is the subdirectory of a data directory to store downloaded
@@ -234,7 +234,7 @@ func (d *DNSFilter) loadFilters(array []FilterYAML) {
 }
 
 func deduplicateFilters(filters []FilterYAML) (deduplicated []FilterYAML) {
-	urls := stringutil.NewSet()
+	urls := container.NewMapSet[string]()
 	lastIdx := 0
 
 	for _, filter := range filters {
diff --git a/internal/filtering/filtering.go b/internal/filtering/filtering.go
index df2f4bc7..4ea57eea 100644
--- a/internal/filtering/filtering.go
+++ b/internal/filtering/filtering.go
@@ -20,11 +20,11 @@ import (
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/hostsfile"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/mathutil"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/syncutil"
 	"github.com/AdguardTeam/urlfilter"
 	"github.com/AdguardTeam/urlfilter/filterlist"
@@ -629,7 +629,7 @@ func (d *DNSFilter) processRewrites(host string, qtype uint16) (res Result) {
 
 	res.Reason = Rewritten
 
-	cnames := stringutil.NewSet()
+	cnames := container.NewMapSet[string]()
 	origHost := host
 	for matched && len(rewrites) > 0 && rewrites[0].Type == dns.TypeCNAME {
 		rw := rewrites[0]
diff --git a/internal/filtering/idgenerator.go b/internal/filtering/idgenerator.go
index b7c0544b..e50f86ee 100644
--- a/internal/filtering/idgenerator.go
+++ b/internal/filtering/idgenerator.go
@@ -5,6 +5,7 @@ import (
 	"sync/atomic"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering/rulelist"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/log"
 )
 
@@ -41,7 +42,7 @@ func (g *idGenerator) next() (id rulelist.URLFilterID) {
 
 // fix ensures that flts all have unique IDs.
 func (g *idGenerator) fix(flts []FilterYAML) {
-	set := map[rulelist.URLFilterID]struct{}{}
+	set := container.NewMapSet[rulelist.URLFilterID]()
 	for i, f := range flts {
 		id := f.ID
 		if id == 0 {
@@ -49,14 +50,14 @@ func (g *idGenerator) fix(flts []FilterYAML) {
 			flts[i].ID = id
 		}
 
-		if _, ok := set[id]; !ok {
-			set[id] = struct{}{}
+		if !set.Has(id) {
+			set.Add(id)
 
 			continue
 		}
 
 		newID := g.next()
-		for _, ok := set[newID]; ok; _, ok = set[newID] {
+		for set.Has(newID) {
 			newID = g.next()
 		}
 
@@ -68,6 +69,6 @@ func (g *idGenerator) fix(flts []FilterYAML) {
 		)
 
 		flts[i].ID = newID
-		set[newID] = struct{}{}
+		set.Add(newID)
 	}
 }
diff --git a/internal/filtering/rewrite/storage.go b/internal/filtering/rewrite/storage.go
index cdf3e52c..42b36273 100644
--- a/internal/filtering/rewrite/storage.go
+++ b/internal/filtering/rewrite/storage.go
@@ -7,8 +7,8 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/urlfilter"
 	"github.com/AdguardTeam/urlfilter/filterlist"
 	"github.com/AdguardTeam/urlfilter/rules"
@@ -85,7 +85,7 @@ func (s *DefaultStorage) MatchRequest(dReq *urlfilter.DNSRequest) (rws []*rules.
 	}
 
 	// TODO(a.garipov): Check cnames for cycles on initialization.
-	cnames := stringutil.NewSet()
+	cnames := container.NewMapSet[string]()
 	host := dReq.Hostname
 	for len(rrules) > 0 && rrules[0].DNSRewrite != nil && rrules[0].DNSRewrite.NewCNAME != "" {
 		rule := rrules[0]
diff --git a/internal/home/clients.go b/internal/home/clients.go
index fb627a2e..2d5b1231 100644
--- a/internal/home/clients.go
+++ b/internal/home/clients.go
@@ -19,6 +19,7 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/whois"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/dnsproxy/upstream"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/hostsfile"
 	"github.com/AdguardTeam/golibs/log"
@@ -54,7 +55,7 @@ type clientsContainer struct {
 	// ipToRC maps IP addresses to runtime client information.
 	ipToRC map[netip.Addr]*client.Runtime
 
-	allTags *stringutil.Set
+	allTags *container.MapSet[string]
 
 	// dhcp is the DHCP service implementation.
 	dhcp DHCP
@@ -108,7 +109,7 @@ func (clients *clientsContainer) Init(
 
 	clients.clientIndex = client.NewIndex()
 
-	clients.allTags = stringutil.NewSet(clientTags...)
+	clients.allTags = container.NewMapSet(clientTags...)
 
 	// TODO(e.burkov):  Use [dhcpsvc] implementation when it's ready.
 	clients.dhcp = dhcpServer
@@ -213,7 +214,7 @@ type clientObject struct {
 // toPersistent returns an initialized persistent client if there are no errors.
 func (o *clientObject) toPersistent(
 	filteringConf *filtering.Config,
-	allTags *stringutil.Set,
+	allTags *container.MapSet[string],
 ) (cli *client.Persistent, err error) {
 	cli = &client.Persistent{
 		Name: o.Name,
@@ -307,8 +308,8 @@ func (clients *clientsContainer) forConfig() (objs []*clientObject) {
 			BlockedServices: cli.BlockedServices.Clone(),
 
 			IDs:       cli.IDs(),
-			Tags:      stringutil.CloneSlice(cli.Tags),
-			Upstreams: stringutil.CloneSlice(cli.Upstreams),
+			Tags:      slices.Clone(cli.Tags),
+			Upstreams: slices.Clone(cli.Upstreams),
 
 			UID: cli.UID,
 
diff --git a/internal/home/i18n.go b/internal/home/i18n.go
index 267205d3..d49ca2fa 100644
--- a/internal/home/i18n.go
+++ b/internal/home/i18n.go
@@ -5,12 +5,12 @@ import (
 	"net/http"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/AdguardTeam/golibs/stringutil"
 )
 
 // TODO(a.garipov): Get rid of a global or generate from .twosky.json.
-var allowedLanguages = stringutil.NewSet(
+var allowedLanguages = container.NewMapSet(
 	"ar",
 	"be",
 	"bg",
diff --git a/internal/ipset/ipset_linux.go b/internal/ipset/ipset_linux.go
index 4cf1fe12..61af2296 100644
--- a/internal/ipset/ipset_linux.go
+++ b/internal/ipset/ipset_linux.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/AdguardTeam/golibs/container"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/digineo/go-ipset/v2"
@@ -174,18 +175,6 @@ func (p *props) parseAttrData(a netfilter.Attribute) {
 	}
 }
 
-// unit is a convenient alias for struct{}.
-type unit = struct{}
-
-// ipsInIpset is the type of a set of IP-address-to-ipset mappings.
-type ipsInIpset map[ipInIpsetEntry]unit
-
-// ipInIpsetEntry is the type for entries in an ipsInIpset set.
-type ipInIpsetEntry struct {
-	ipsetName string
-	ipArr     [net.IPv6len]byte
-}
-
 // manager is the Linux Netfilter ipset manager.
 type manager struct {
 	nameToIpset    map[string]props
@@ -196,17 +185,23 @@ type manager struct {
 	// mu protects all properties below.
 	mu *sync.Mutex
 
-	// TODO(a.garipov): Currently, the ipset list is static, and we don't
-	// read the IPs already in sets, so we can assume that all incoming IPs
-	// are either added to all corresponding ipsets or not.  When that stops
-	// being the case, for example if we add dynamic reconfiguration of
-	// ipsets, this map will need to become a per-ipset-name one.
-	addedIPs ipsInIpset
+	// TODO(a.garipov): Currently, the ipset list is static, and we don't read
+	// the IPs already in sets, so we can assume that all incoming IPs are
+	// either added to all corresponding ipsets or not.  When that stops being
+	// the case, for example if we add dynamic reconfiguration of ipsets, this
+	// map will need to become a per-ipset-name one.
+	addedIPs *container.MapSet[ipInIpsetEntry]
 
 	ipv4Conn ipsetConn
 	ipv6Conn ipsetConn
 }
 
+// ipInIpsetEntry is the type for entries in [manager.addIPs].
+type ipInIpsetEntry struct {
+	ipsetName string
+	ipArr     [net.IPv6len]byte
+}
+
 // dialNetfilter establishes connections to Linux's netfilter module.
 func (m *manager) dialNetfilter(conf *netlink.Config) (err error) {
 	// The kernel API does not actually require two sockets but package
@@ -372,7 +367,7 @@ func newManagerWithDialer(ipsetConf []string, dial dialer) (mgr Manager, err err
 
 		dial: dial,
 
-		addedIPs: make(ipsInIpset),
+		addedIPs: container.NewMapSet[ipInIpsetEntry](),
 	}
 
 	err = m.dialNetfilter(&netlink.Config{})
@@ -438,7 +433,7 @@ func (m *manager) addIPs(host string, set props, ips []net.IP) (n int, err error
 		}
 		copy(e.ipArr[:], ip.To16())
 
-		if _, added := m.addedIPs[e]; added {
+		if m.addedIPs.Has(e) {
 			continue
 		}
 
@@ -471,7 +466,7 @@ func (m *manager) addIPs(host string, set props, ips []net.IP) (n int, err error
 	for _, e := range newAddedEntries {
 		s := m.nameToIpset[e.ipsetName]
 		if s.isPersistent {
-			m.addedIPs[e] = unit{}
+			m.addedIPs.Add(e)
 		}
 	}
 
diff --git a/internal/querylog/http.go b/internal/querylog/http.go
index 3e71af57..1fb7cce4 100644
--- a/internal/querylog/http.go
+++ b/internal/querylog/http.go
@@ -7,6 +7,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -15,7 +16,6 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/timeutil"
 	"golang.org/x/net/idna"
 )
@@ -308,7 +308,7 @@ func parseSearchCriterion(q url.Values, name string, ct criterionType) (
 			asciiVal = ""
 		}
 	case ctFilteringStatus:
-		if !stringutil.InSlice(filteringStatusValues, val) {
+		if !slices.Contains(filteringStatusValues, val) {
 			return false, sc, fmt.Errorf("invalid value %s", val)
 		}
 	default:
diff --git a/scripts/translations/upload.go b/scripts/translations/upload.go
index b9cfd4bf..dcad4084 100644
--- a/scripts/translations/upload.go
+++ b/scripts/translations/upload.go
@@ -52,7 +52,7 @@ func prepareMultipartMsg(
 	w := multipart.NewWriter(buf)
 	var fw io.Writer
 
-	err = mapsutil.OrderedRangeError(formData, w.WriteField)
+	err = mapsutil.SortedRangeError(formData, w.WriteField)
 	if err != nil {
 		return nil, "", fmt.Errorf("writing field: %w", err)
 	}