diff --git a/internal/home/config.go b/internal/home/config.go
index 8ddb691d..c010a414 100644
--- a/internal/home/config.go
+++ b/internal/home/config.go
@@ -163,8 +163,10 @@ type configuration struct {
 	// [configmigrate.LastSchemaVersion].
 	SchemaVersion uint `yaml:"schema_version"`
 
-	// UnsafeCustomUpdateIndexURL is the URL to the custom update index.  It's
-	// only used in testing purposes and should not be used in release.
+	// UnsafeCustomUpdateIndexURL is the URL to the custom update index.
+	//
+	// NOTE: It's only exists for testing purposes and should not be used in
+	// release.
 	UnsafeCustomUpdateIndexURL bool `yaml:"unsafe_custom_update_index_url,omitempty"`
 }
 
diff --git a/internal/home/controlupdate.go b/internal/home/controlupdate.go
index acf3e0dd..aeab8810 100644
--- a/internal/home/controlupdate.go
+++ b/internal/home/controlupdate.go
@@ -75,7 +75,7 @@ func (web *webAPI) handleVersionJSON(w http.ResponseWriter, r *http.Request) {
 // update server.
 func (web *webAPI) requestVersionInfo(resp *versionResponse, recheck bool) (err error) {
 	updater := web.conf.updater
-	for i := 0; i != 3; i++ {
+	for range 3 {
 		resp.VersionInfo, err = updater.VersionInfo(recheck)
 		if err == nil {
 			return nil
@@ -87,9 +87,10 @@ func (web *webAPI) requestVersionInfo(resp *versionResponse, recheck bool) (err
 			// restarting our DNS server.  Log and sleep for some time.
 			//
 			// See https://github.com/AdguardTeam/AdGuardHome/issues/934.
-			d := time.Duration(i) * time.Second
-			log.Info("update: temp net error: %q; sleeping for %s and retrying", err, d)
-			time.Sleep(d)
+			const sleepTime = 2 * time.Second
+
+			log.Info("update: temp net error: %v; sleeping for %s and retrying", err, sleepTime)
+			time.Sleep(sleepTime)
 
 			continue
 		}
diff --git a/internal/home/home.go b/internal/home/home.go
index d6f11489..a7547ae6 100644
--- a/internal/home/home.go
+++ b/internal/home/home.go
@@ -606,11 +606,11 @@ func run(opts options, clientBuildFS fs.FS, done chan struct{}) {
 
 	confPath := configFilePath()
 
-	upd := newUpdater(Context.workDir, confPath, execPath, config)
+	upd := newUpdater(ctx, slogLogger, Context.workDir, confPath, execPath, config)
 
 	// TODO(e.burkov): This could be made earlier, probably as the option's
 	// effect.
-	cmdlineUpdate(opts, upd, slogLogger)
+	cmdlineUpdate(ctx, slogLogger, opts, upd)
 
 	if !Context.firstRun {
 		// Save the updated config.
@@ -679,20 +679,40 @@ func run(opts options, clientBuildFS fs.FS, done chan struct{}) {
 }
 
 // newUpdater creates a new AdGuard Home updater.
-func newUpdater(workDir, confPath, execPath string, config *configuration) (upd *updater.Updater) {
+func newUpdater(
+	ctx context.Context,
+	l *slog.Logger,
+	workDir string,
+	confPath string,
+	execPath string,
+	config *configuration,
+) (upd *updater.Updater) {
 	// envName is the name of the environment variable that can be used to
 	// override the default version check URL.
 	const envName = "ADGUARD_HOME_TEST_UPDATE_VERSION_URL"
 
+	customURLStr := os.Getenv(envName)
+
 	var versionURL *url.URL
-	if version.Channel() == version.ChannelRelease || !config.UnsafeCustomUpdateIndexURL {
-		// Go on, use the default URL.
-	} else if versionURLStr, ok := os.LookupEnv(envName); ok {
+	switch {
+	case
+		// Only enable custom update URL for development builds.
+		version.Channel() == version.ChannelRelease,
+		!config.UnsafeCustomUpdateIndexURL:
+		// Go on and use the default URL.
+	case customURLStr != "":
 		var err error
-		versionURL, err = url.Parse(versionURLStr)
+		versionURL, err = url.Parse(customURLStr)
 		if err != nil {
-			log.Error(envName+" is not a valid URL: %s", err)
+			l.ErrorContext(
+				ctx,
+				"invalid environment variable value",
+				"env", envName,
+				slogutil.KeyError, err,
+			)
 		}
+	default:
+		l.DebugContext(ctx, "environment variable value is not specified", "env", envName)
 	}
 
 	if versionURL == nil {
@@ -703,7 +723,7 @@ func newUpdater(workDir, confPath, execPath string, config *configuration) (upd
 		}
 	}
 
-	log.Debug("using config path %q for updater", confPath)
+	l.DebugContext(ctx, "creating updater", "config_path", confPath)
 
 	return updater.NewUpdater(&updater.Config{
 		Client:          config.Filtering.HTTPClient,
@@ -1023,7 +1043,7 @@ type jsonError struct {
 }
 
 // cmdlineUpdate updates current application and exits.  l must not be nil.
-func cmdlineUpdate(opts options, upd *updater.Updater, l *slog.Logger) {
+func cmdlineUpdate(ctx context.Context, l *slog.Logger, opts options, upd *updater.Updater) {
 	if !opts.performUpdate {
 		return
 	}
@@ -1036,19 +1056,19 @@ func cmdlineUpdate(opts options, upd *updater.Updater, l *slog.Logger) {
 	err := initDNSServer(nil, nil, nil, nil, nil, nil, &tlsConfigSettings{}, l)
 	fatalOnError(err)
 
-	log.Info("cmdline update: performing update")
+	l.InfoContext(ctx, "performing update via cli")
 
 	info, err := upd.VersionInfo(true)
 	if err != nil {
-		log.Error("getting version info: %s", err)
+		l.ErrorContext(ctx, "getting version info", slogutil.KeyError, err)
 
-		os.Exit(1)
+		os.Exit(osutil.ExitCodeFailure)
 	}
 
 	if info.NewVersion == version.Version() {
-		log.Info("no updates available")
+		l.InfoContext(ctx, "no updates available")
 
-		os.Exit(0)
+		os.Exit(osutil.ExitCodeSuccess)
 	}
 
 	err = upd.Update(Context.firstRun)
@@ -1056,10 +1076,10 @@ func cmdlineUpdate(opts options, upd *updater.Updater, l *slog.Logger) {
 
 	err = restartService()
 	if err != nil {
-		log.Debug("restarting service: %s", err)
-		log.Info("AdGuard Home was not installed as a service. " +
+		l.DebugContext(ctx, "restarting service", slogutil.KeyError, err)
+		l.InfoContext(ctx, "AdGuard Home was not installed as a service. "+
 			"Please restart running instances of AdGuardHome manually.")
 	}
 
-	os.Exit(0)
+	os.Exit(osutil.ExitCodeSuccess)
 }
diff --git a/internal/updater/updater_internal_test.go b/internal/updater/updater_internal_test.go
index 0ed94641..362699e0 100644
--- a/internal/updater/updater_internal_test.go
+++ b/internal/updater/updater_internal_test.go
@@ -76,7 +76,8 @@ func TestUpdater_internal(t *testing.T) {
 
 		u.clean()
 
-		t.Run("backup", func(t *testing.T) {
+		// Consider the following subtest necessary.
+		require.True(t, t.Run("backup", func(t *testing.T) {
 			var d []byte
 			d, err = os.ReadFile(filepath.Join(wd, "agh-backup", "AdGuardHome.yaml"))
 			require.NoError(t, err)
@@ -87,7 +88,7 @@ func TestUpdater_internal(t *testing.T) {
 			require.NoError(t, err)
 
 			assert.Equal(t, tc.exeName, string(d))
-		})
+		}))
 
 		t.Run("updated", func(t *testing.T) {
 			var d []byte