diff --git a/internal/confmigrate/migrations_test.go b/internal/confmigrate/migrations_test.go
index 5e9ea657..513646e8 100644
--- a/internal/confmigrate/migrations_test.go
+++ b/internal/confmigrate/migrations_test.go
@@ -96,7 +96,7 @@ func TestUpgradeSchema5to6(t *testing.T) {
 		},
 		want: yobj{
 			"clients": yarr{yobj{
-				"ids": []string{"127.0.0.1"},
+				"ids": yarr{"127.0.0.1"},
 				"ip":  "127.0.0.1",
 			}},
 			"schema_version": newSchemaVer,
@@ -109,7 +109,7 @@ func TestUpgradeSchema5to6(t *testing.T) {
 		},
 		want: yobj{
 			"clients": yarr{yobj{
-				"ids": []string{"mac"},
+				"ids": yarr{"mac"},
 				"mac": "mac",
 			}},
 			"schema_version": newSchemaVer,
@@ -122,7 +122,7 @@ func TestUpgradeSchema5to6(t *testing.T) {
 		},
 		want: yobj{
 			"clients": yarr{yobj{
-				"ids": []string{"127.0.0.1", "mac"},
+				"ids": yarr{"127.0.0.1", "mac"},
 				"ip":  "127.0.0.1",
 				"mac": "mac",
 			}},
diff --git a/internal/confmigrate/v10.go b/internal/confmigrate/v10.go
index 81641897..0cf10c2f 100644
--- a/internal/confmigrate/v10.go
+++ b/internal/confmigrate/v10.go
@@ -34,36 +34,47 @@ func migrateTo10(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 10
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	const quicPort = 784
 
-	for _, upsField := range []string{
-		"upstream_dns",
-		"local_ptr_upstreams",
-	} {
-		var ups yarr
-		ups, ok, err = fieldVal[yarr](dns, upsField)
-		if err != nil {
+	ups, ok, err := fieldVal[yarr](dns, "upstream_dns")
+	if err != nil {
+		return err
+	} else if ok {
+		if err = addQUICPorts(ups, quicPort); err != nil {
 			return err
-		} else if !ok {
-			continue
 		}
 
-		var u string
-		for i, uVal := range ups {
-			u, ok = uVal.(string)
-			if !ok {
-				return fmt.Errorf("unexpected type of upstream field: %T", uVal)
-			}
+		dns["upstream_dns"] = ups
+	}
 
-			ups[i] = addQUICPort(u, quicPort)
+	ups, ok, err = fieldVal[yarr](dns, "local_ptr_upstreams")
+	if err != nil {
+		return err
+	} else if ok {
+		if err = addQUICPorts(ups, quicPort); err != nil {
+			return err
 		}
-		dns[upsField] = ups
+
+		dns["local_ptr_upstreams"] = ups
+	}
+
+	return nil
+}
+
+// addQUICPorts inserts a port into each QUIC upstream's hostname in ups if
+// those are missing.
+func addQUICPorts(ups yarr, port int) (err error) {
+	for i, uVal := range ups {
+		u, ok := uVal.(string)
+		if !ok {
+			return fmt.Errorf("unexpected type of upstream field: %T", uVal)
+		}
+
+		ups[i] = addQUICPort(u, port)
 	}
 
 	return nil
diff --git a/internal/confmigrate/v12.go b/internal/confmigrate/v12.go
index 078f8bc6..6703561a 100644
--- a/internal/confmigrate/v12.go
+++ b/internal/confmigrate/v12.go
@@ -21,18 +21,18 @@ func migrateTo12(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 12
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	const field = "querylog_interval"
 
 	qlogIvl, ok, err := fieldVal[int](dns, field)
-	if err != nil {
-		return err
-	} else if !ok {
+	if !ok {
+		if err != nil {
+			return err
+		}
+
 		// Set the initial value from home.initConfig function.
 		qlogIvl = 90
 	}
diff --git a/internal/confmigrate/v13.go b/internal/confmigrate/v13.go
index 27afa25d..a69592bf 100644
--- a/internal/confmigrate/v13.go
+++ b/internal/confmigrate/v13.go
@@ -19,17 +19,13 @@ func migrateTo13(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 13
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	dhcp, ok, err := fieldVal[yobj](diskConf, "dhcp")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	return moveSameVal[string](dns, dhcp, "local_domain_name")
diff --git a/internal/confmigrate/v14.go b/internal/confmigrate/v14.go
index 1f5812f8..d259a2a6 100644
--- a/internal/confmigrate/v14.go
+++ b/internal/confmigrate/v14.go
@@ -31,35 +31,32 @@ func migrateTo14(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 14
 
 	persistent, ok, err := fieldVal[yarr](diskConf, "clients")
-	if err != nil {
-		return err
-	} else if !ok {
+	if !ok {
+		if err != nil {
+			return err
+		}
+
 		persistent = yarr{}
 	}
 
-	var rdnsSrc bool
+	runtimeClients := yobj{
+		"whois": true,
+		"arp":   true,
+		"rdns":  false,
+		"dhcp":  true,
+		"hosts": true,
+	}
+	diskConf["clients"] = yobj{
+		"persistent":      persistent,
+		"runtime_sources": runtimeClients,
+	}
+
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
 	if err != nil {
 		return err
-	} else if ok {
-		rdnsSrc, ok, err = fieldVal[bool](dns, "resolve_clients")
-		if err != nil {
-			return err
-		} else if ok {
-			delete(dns, "resolve_clients")
-		}
+	} else if !ok {
+		return nil
 	}
 
-	diskConf["clients"] = yobj{
-		"persistent": persistent,
-		"runtime_sources": yobj{
-			"whois": true,
-			"arp":   true,
-			"rdns":  rdnsSrc,
-			"dhcp":  true,
-			"hosts": true,
-		},
-	}
-
-	return nil
+	return moveVal[bool](dns, runtimeClients, "resolve_clients", "rdns")
 }
diff --git a/internal/confmigrate/v15.go b/internal/confmigrate/v15.go
index 6cd0e3e6..904ef110 100644
--- a/internal/confmigrate/v15.go
+++ b/internal/confmigrate/v15.go
@@ -30,10 +30,8 @@ func migrateTo15(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 15
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	qlog := map[string]any{
@@ -43,17 +41,12 @@ func migrateTo15(diskConf yobj) (err error) {
 		"interval":     "2160h",
 		"size_memory":  1000,
 	}
-	err = coalesceError(
-		moveVal[bool](dns, qlog, "querylog_enabled", "enabled"),
-		moveVal[bool](dns, qlog, "querylog_file_enabled", "file_enabled"),
-		moveVal[string](dns, qlog, "querylog_interval", "interval"),
-		moveVal[int](dns, qlog, "querylog_size_memory", "size_memory"),
-	)
-	if err != nil {
-		return err
-	}
-
 	diskConf["querylog"] = qlog
 
-	return nil
+	return coalesceError(
+		moveVal[bool](dns, qlog, "querylog_enabled", "enabled"),
+		moveVal[bool](dns, qlog, "querylog_file_enabled", "file_enabled"),
+		moveVal[any](dns, qlog, "querylog_interval", "interval"),
+		moveVal[int](dns, qlog, "querylog_size_memory", "size_memory"),
+	)
 }
diff --git a/internal/confmigrate/v16.go b/internal/confmigrate/v16.go
index 3722a53d..b174d4cb 100644
--- a/internal/confmigrate/v16.go
+++ b/internal/confmigrate/v16.go
@@ -47,10 +47,8 @@ func migrateTo16(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 16
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	stats := yobj{
@@ -58,24 +56,23 @@ func migrateTo16(diskConf yobj) (err error) {
 		"interval": 1,
 		"ignored":  yarr{},
 	}
+	diskConf["statistics"] = stats
 
 	const field = "statistics_interval"
 
 	statsIvl, ok, err := fieldVal[int](dns, field)
-	if err != nil {
+	if !ok {
 		return err
-	} else if ok {
-		if statsIvl == 0 {
-			// Set the interval to the default value of one day to make sure
-			// that it passes the validations.
-			stats["enabled"] = false
-		} else {
-			stats["interval"] = statsIvl
-		}
-		delete(dns, field)
 	}
 
-	diskConf["statistics"] = stats
+	if statsIvl == 0 {
+		// Set the interval to the default value of one day to make sure
+		// that it passes the validations.
+		stats["enabled"] = false
+	} else {
+		stats["interval"] = statsIvl
+	}
+	delete(dns, field)
 
 	return nil
 }
diff --git a/internal/confmigrate/v17.go b/internal/confmigrate/v17.go
index 97dc3b3d..a3a04460 100644
--- a/internal/confmigrate/v17.go
+++ b/internal/confmigrate/v17.go
@@ -22,10 +22,8 @@ func migrateTo17(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 17
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	const field = "edns_client_subnet"
diff --git a/internal/confmigrate/v18.go b/internal/confmigrate/v18.go
index cc90b007..28c55723 100644
--- a/internal/confmigrate/v18.go
+++ b/internal/confmigrate/v18.go
@@ -26,10 +26,8 @@ func migrateTo18(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 18
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	safeSearch := yobj{
@@ -41,7 +39,6 @@ func migrateTo18(diskConf yobj) (err error) {
 		"yandex":     true,
 		"youtube":    true,
 	}
-
 	dns["safe_search"] = safeSearch
 
 	return moveVal[bool](dns, safeSearch, "safesearch_enabled", "enabled")
diff --git a/internal/confmigrate/v19.go b/internal/confmigrate/v19.go
index 317e44c2..6fbb6d4f 100644
--- a/internal/confmigrate/v19.go
+++ b/internal/confmigrate/v19.go
@@ -34,10 +34,8 @@ func migrateTo19(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 19
 
 	clients, ok, err := fieldVal[yobj](diskConf, "clients")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	persistent, ok, _ := fieldVal[yarr](clients, "persistent")
diff --git a/internal/confmigrate/v20.go b/internal/confmigrate/v20.go
index 64813ce6..e86c36c7 100644
--- a/internal/confmigrate/v20.go
+++ b/internal/confmigrate/v20.go
@@ -25,10 +25,8 @@ func migrateTo20(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 20
 
 	stats, ok, err := fieldVal[yobj](diskConf, "statistics")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	const field = "interval"
diff --git a/internal/confmigrate/v21.go b/internal/confmigrate/v21.go
index fd074da7..afda11bf 100644
--- a/internal/confmigrate/v21.go
+++ b/internal/confmigrate/v21.go
@@ -28,10 +28,8 @@ func migrateTo21(diskConf yobj) (err error) {
 	const field = "blocked_services"
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	svcs := yobj{
diff --git a/internal/confmigrate/v22.go b/internal/confmigrate/v22.go
index 70bb23f4..4d5de732 100644
--- a/internal/confmigrate/v22.go
+++ b/internal/confmigrate/v22.go
@@ -36,17 +36,13 @@ func migrateTo22(diskConf yobj) (err error) {
 	const field = "blocked_services"
 
 	clients, ok, err := fieldVal[yobj](diskConf, "clients")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	persistent, ok, err := fieldVal[yarr](clients, "persistent")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	for i, p := range persistent {
diff --git a/internal/confmigrate/v23.go b/internal/confmigrate/v23.go
index 34cee315..6cbcbcf5 100644
--- a/internal/confmigrate/v23.go
+++ b/internal/confmigrate/v23.go
@@ -27,10 +27,8 @@ func migrateTo23(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 23
 
 	bindHost, ok, err := fieldVal[string](diskConf, "bind_host")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	bindHostAddr, err := netip.ParseAddr(bindHost)
diff --git a/internal/confmigrate/v25.go b/internal/confmigrate/v25.go
index 25ab7858..e574610e 100644
--- a/internal/confmigrate/v25.go
+++ b/internal/confmigrate/v25.go
@@ -18,14 +18,13 @@ func migrateTo25(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 25
 
 	httpObj, ok, err := fieldVal[yobj](diskConf, "http")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	pprofObj := yobj{
-		"port": 6060,
+		"enabled": false,
+		"port":    6060,
 	}
 
 	err = moveVal[bool](diskConf, pprofObj, "debug_pprof", "enabled")
diff --git a/internal/confmigrate/v26.go b/internal/confmigrate/v26.go
index 88e10140..5ead91df 100644
--- a/internal/confmigrate/v26.go
+++ b/internal/confmigrate/v26.go
@@ -73,10 +73,8 @@ func migrateTo26(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 26
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	filteringObj := yobj{}
diff --git a/internal/confmigrate/v3.go b/internal/confmigrate/v3.go
index 0f522b51..8220c5df 100644
--- a/internal/confmigrate/v3.go
+++ b/internal/confmigrate/v3.go
@@ -14,24 +14,18 @@ package confmigrate
 //	  'bootstrap_dns':
 //	  - '1.1.1.1'
 //	  # …
-func migrateTo3(diskConf yobj) error {
+func migrateTo3(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 3
 
 	dnsConfig, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	bootstrapDNS, ok, err := fieldVal[any](dnsConfig, "bootstrap_dns")
-	if err != nil {
-		return err
-	} else if !ok {
-		return nil
+	if ok {
+		dnsConfig["bootstrap_dns"] = yarr{bootstrapDNS}
 	}
 
-	dnsConfig["bootstrap_dns"] = yarr{bootstrapDNS}
-
-	return nil
+	return err
 }
diff --git a/internal/confmigrate/v4.go b/internal/confmigrate/v4.go
index 8ea8155e..467cc05c 100644
--- a/internal/confmigrate/v4.go
+++ b/internal/confmigrate/v4.go
@@ -6,20 +6,21 @@ package confmigrate
 //	'schema_version': 3
 //	'clients':
 //	- # …
+//	# …
 //
 //	# AFTER:
 //	'schema_version': 4
 //	'clients':
 //	- 'use_global_blocked_services': true
 //	  # …
+//	# …
 func migrateTo4(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 4
 
 	clients, ok, _ := fieldVal[yarr](diskConf, "clients")
 	if ok {
 		for i := range clients {
-			var c yobj
-			if c, ok = clients[i].(yobj); ok {
+			if c, isYobj := clients[i].(yobj); isYobj {
 				c["use_global_blocked_services"] = true
 			}
 		}
diff --git a/internal/confmigrate/v5.go b/internal/confmigrate/v5.go
index aed006d0..7bdd4d00 100644
--- a/internal/confmigrate/v5.go
+++ b/internal/confmigrate/v5.go
@@ -30,10 +30,8 @@ func migrateTo5(diskConf yobj) (err error) {
 	}
 
 	pass, ok, err := fieldVal[string](diskConf, "auth_pass")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 	delete(diskConf, "auth_pass")
 
diff --git a/internal/confmigrate/v6.go b/internal/confmigrate/v6.go
index 2767a4c0..aa741ba9 100644
--- a/internal/confmigrate/v6.go
+++ b/internal/confmigrate/v6.go
@@ -10,24 +10,26 @@ import "fmt"
 //	 - # …
 //	   'ip': '127.0.0.1'
 //	   'mac': 'AA:AA:AA:AA:AA:AA'
+//	  # …
 //	# …
 //
 //	# AFTER:
 //	'schema_version': 6
 //	'clients':
 //	 - # …
+//	   'ip': '127.0.0.1'
+//	   'mac': 'AA:AA:AA:AA:AA:AA'
 //	   'ids':
 //	   - '127.0.0.1'
 //	   - 'AA:AA:AA:AA:AA:AA'
+//	  # …
 //	# …
 func migrateTo6(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 6
 
 	clients, ok, err := fieldVal[yarr](diskConf, "clients")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	for i, client := range clients {
@@ -37,22 +39,14 @@ func migrateTo6(diskConf yobj) (err error) {
 			return fmt.Errorf("unexpected type of client at index %d: %T", i, client)
 		}
 
-		var ids []string
-
-		var ip string
-		ip, _, err = fieldVal[string](c, "ip")
-		if err != nil {
-			return fmt.Errorf("client at index %d: %w", i, err)
-		} else if ip != "" {
-			ids = append(ids, ip)
-		}
-
-		var mac string
-		mac, _, err = fieldVal[string](c, "mac")
-		if err != nil {
-			return fmt.Errorf("client at index %d: %w", i, err)
-		} else if mac != "" {
-			ids = append(ids, mac)
+		ids := yarr{}
+		for _, id := range []string{"ip", "mac"} {
+			val, _, valErr := fieldVal[string](c, id)
+			if valErr != nil {
+				return fmt.Errorf("client at index %d: %w", i, valErr)
+			} else if val != "" {
+				ids = append(ids, val)
+			}
 		}
 
 		c["ids"] = ids
diff --git a/internal/confmigrate/v7.go b/internal/confmigrate/v7.go
index 904bb88d..1db348bd 100644
--- a/internal/confmigrate/v7.go
+++ b/internal/confmigrate/v7.go
@@ -28,11 +28,11 @@ package confmigrate
 //	    'lease_duration': 86400
 //	    'icmp_timeout_msec': 1000
 //	# …
-func migrateTo7(diskConf yobj) error {
+func migrateTo7(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 7
 
-	dhcp, ok, err := fieldVal[yobj](diskConf, "dhcp")
-	if err != nil || !ok {
+	dhcp, ok, _ := fieldVal[yobj](diskConf, "dhcp")
+	if !ok {
 		return nil
 	}
 
diff --git a/internal/confmigrate/v8.go b/internal/confmigrate/v8.go
index 50c31fd4..f8075dfb 100644
--- a/internal/confmigrate/v8.go
+++ b/internal/confmigrate/v8.go
@@ -20,17 +20,13 @@ func migrateTo8(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 8
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	bindHost, ok, err := fieldVal[string](dns, "bind_host")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	delete(dns, "bind_host")
diff --git a/internal/confmigrate/v9.go b/internal/confmigrate/v9.go
index eba74ec7..b8fc9a72 100644
--- a/internal/confmigrate/v9.go
+++ b/internal/confmigrate/v9.go
@@ -19,10 +19,8 @@ func migrateTo9(diskConf yobj) (err error) {
 	diskConf["schema_version"] = 9
 
 	dns, ok, err := fieldVal[yobj](diskConf, "dns")
-	if err != nil {
+	if !ok {
 		return err
-	} else if !ok {
-		return nil
 	}
 
 	return moveVal[string](dns, dns, "autohost_tld", "local_domain_name")
diff --git a/internal/confmigrate/yaml.go b/internal/confmigrate/yaml.go
index 3e097b52..778cd1fd 100644
--- a/internal/confmigrate/yaml.go
+++ b/internal/confmigrate/yaml.go
@@ -1,6 +1,8 @@
 package confmigrate
 
-import "fmt"
+import (
+	"fmt"
+)
 
 type (
 	// yarr is the convenience alias for YAML array.
diff --git a/scripts/make/go-lint.sh b/scripts/make/go-lint.sh
index 9a2fc2a5..f08fcd47 100644
--- a/scripts/make/go-lint.sh
+++ b/scripts/make/go-lint.sh
@@ -177,7 +177,6 @@ run_linter gocyclo --over 10 .
 gocognit_paths="\
 ./internal/aghnet/   20
 ./internal/querylog/ 20
-./internal/confmigrate/ 19
 ./internal/dnsforward/  19
 ./internal/home/        19
 ./internal/aghtls/ 18
@@ -194,6 +193,7 @@ gocognit_paths="\
 ./internal/aghrenameio/          10
 ./internal/arpdb/                10
 ./internal/client/               10
+./internal/confmigrate/          10
 ./internal/dhcpsvc               10
 ./internal/filtering/hashprefix/ 10
 ./internal/filtering/rulelist/   10