diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a276ffc090..74a25d2dfb4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,8 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Fixed
 
+- Support for link-local subnets, i.e. `fe80::/16`, as client identifiers
+  ([#6312]).
 - Support for link-local subnets, i.e. `fe80::/16`, in the access settings
   ([#6192]).
 - The ability to apply an invalid configuration for private RDNS, which led to
@@ -43,6 +45,7 @@ NOTE: Add new changes BELOW THIS COMMENT.
 [#5345]: https://github.com/AdguardTeam/AdGuardHome/issues/5345
 [#5812]: https://github.com/AdguardTeam/AdGuardHome/issues/5812
 [#6192]: https://github.com/AdguardTeam/AdGuardHome/issues/6192
+[#6312]: https://github.com/AdguardTeam/AdGuardHome/issues/6312
 [#6854]: https://github.com/AdguardTeam/AdGuardHome/issues/6854
 [#6875]: https://github.com/AdguardTeam/AdGuardHome/issues/6875
 
diff --git a/internal/client/index.go b/internal/client/index.go
index a7f36c482c7..a3d19cb884f 100644
--- a/internal/client/index.go
+++ b/internal/client/index.go
@@ -192,15 +192,14 @@ func (ci *Index) Find(id string) (c *Persistent, ok bool) {
 
 // find finds persistent client by IP address.
 func (ci *Index) findByIP(ip netip.Addr) (c *Persistent, found bool) {
-	ip = ip.WithZone("")
-
 	uid, found := ci.ipToUID[ip]
 	if found {
 		return ci.uidToClient[uid], true
 	}
 
 	ci.subnetToUID.Range(func(pref netip.Prefix, id UID) (cont bool) {
-		if pref.Contains(ip) {
+		// Remove zone before checking because prefixes stip zones.
+		if pref.Contains(ip.WithZone("")) {
 			uid, found = id, true
 
 			return false
diff --git a/internal/client/index_internal_test.go b/internal/client/index_internal_test.go
index abf38710427..a03d9a221c1 100644
--- a/internal/client/index_internal_test.go
+++ b/internal/client/index_internal_test.go
@@ -35,27 +35,49 @@ func TestClientIndex(t *testing.T) {
 
 		cliID  = "client-id"
 		cliMAC = "11:11:11:11:11:11"
+
+		linkLocalIP     = "fe80::abcd:abcd:abcd:ab%eth0"
+		linkLocalSubnet = "fe80::/16"
 	)
 
-	clients := []*Persistent{{
-		Name: "client1",
-		IPs: []netip.Addr{
-			netip.MustParseAddr(cliIP1),
-			netip.MustParseAddr(cliIPv6),
-		},
-	}, {
-		Name:    "client2",
-		IPs:     []netip.Addr{netip.MustParseAddr(cliIP2)},
-		Subnets: []netip.Prefix{netip.MustParsePrefix(cliSubnet)},
-	}, {
-		Name: "client_with_mac",
-		MACs: []net.HardwareAddr{mustParseMAC(cliMAC)},
-	}, {
-		Name:      "client_with_id",
-		ClientIDs: []string{cliID},
-	}}
+	var (
+		ClientOne = &Persistent{
+			Name: "client1",
+			IPs: []netip.Addr{
+				netip.MustParseAddr(cliIP1),
+				netip.MustParseAddr(cliIPv6),
+			},
+		}
+
+		ClientTwo = &Persistent{
+			Name:    "client2",
+			IPs:     []netip.Addr{netip.MustParseAddr(cliIP2)},
+			Subnets: []netip.Prefix{netip.MustParsePrefix(cliSubnet)},
+		}
+
+		ClientWithMAC = &Persistent{
+			Name: "client_with_mac",
+			MACs: []net.HardwareAddr{mustParseMAC(cliMAC)},
+		}
+
+		ClientWithID = &Persistent{
+			Name:      "client_with_id",
+			ClientIDs: []string{cliID},
+		}
+
+		ClientLinkLocal = &Persistent{
+			Name:    "client_link_local",
+			Subnets: []netip.Prefix{netip.MustParsePrefix(linkLocalSubnet)},
+		}
+	)
 
-	ci := newIDIndex(clients)
+	ci := newIDIndex([]*Persistent{
+		ClientOne,
+		ClientTwo,
+		ClientWithMAC,
+		ClientWithID,
+		ClientLinkLocal,
+	})
 
 	testCases := []struct {
 		want *Persistent
@@ -64,19 +86,23 @@ func TestClientIndex(t *testing.T) {
 	}{{
 		name: "ipv4_ipv6",
 		ids:  []string{cliIP1, cliIPv6},
-		want: clients[0],
+		want: ClientOne,
 	}, {
 		name: "ipv4_subnet",
 		ids:  []string{cliIP2, cliSubnetIP},
-		want: clients[1],
+		want: ClientTwo,
 	}, {
 		name: "mac",
 		ids:  []string{cliMAC},
-		want: clients[2],
+		want: ClientWithMAC,
 	}, {
 		name: "client_id",
 		ids:  []string{cliID},
-		want: clients[3],
+		want: ClientWithID,
+	}, {
+		name: "client_link_local_subnet",
+		ids:  []string{linkLocalIP},
+		want: ClientLinkLocal,
 	}}
 
 	for _, tc := range testCases {
diff --git a/internal/client/persistent.go b/internal/client/persistent.go
index 8345f41896a..06e346f4dfc 100644
--- a/internal/client/persistent.go
+++ b/internal/client/persistent.go
@@ -161,7 +161,7 @@ func (c *Persistent) setID(id string) (err error) {
 
 	var ip netip.Addr
 	if ip, err = netip.ParseAddr(id); err == nil {
-		c.IPs = append(c.IPs, ip.WithZone(""))
+		c.IPs = append(c.IPs, ip)
 
 		return nil
 	}