diff --git a/cmds/portmaster-start/main.go b/cmds/portmaster-start/main.go
index 46df0c89..d6b48f1e 100644
--- a/cmds/portmaster-start/main.go
+++ b/cmds/portmaster-start/main.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/signal"
@@ -14,8 +13,6 @@ import (
 
 	"github.com/safing/portmaster/updates/helper"
 
-	"github.com/tidwall/gjson"
-
 	"github.com/safing/portbase/dataroot"
 	"github.com/safing/portbase/info"
 	portlog "github.com/safing/portbase/log"
@@ -188,11 +185,11 @@ func ensureLoggingDir() error {
 }
 
 func updateRegistryIndex(mustLoadIndex bool) error {
-	// Get release channel from config.
-	releaseChannel := getReleaseChannel(dataRoot)
-
 	// Set indexes based on the release channel.
-	helper.SetIndexes(registry, releaseChannel)
+	warning := helper.SetIndexes(registry, "", false)
+	if warning != nil {
+		log.Printf("WARNING: %s\n", warning)
+	}
 
 	// Load indexes from disk or network, if needed and desired.
 	err := registry.LoadIndexes(context.Background())
@@ -232,26 +229,3 @@ func detectInstallationDir() string {
 
 	return parent
 }
-
-func getReleaseChannel(dataRoot *utils.DirStructure) string {
-	configData, err := ioutil.ReadFile(filepath.Join(dataRoot.Path, "config.json"))
-	if err != nil {
-		if !os.IsNotExist(err) {
-			log.Printf("WARNING: failed to read config.json to get release channel: %s\n", err)
-		}
-		return helper.ReleaseChannelStable
-	}
-
-	// Get release channel from config, validate and return it.
-	channel := gjson.GetBytes(configData, helper.ReleaseChannelJSONKey).String()
-	switch channel {
-	case helper.ReleaseChannelStable,
-		helper.ReleaseChannelBeta,
-		helper.ReleaseChannelStaging,
-		helper.ReleaseChannelSupport:
-		return channel
-	default:
-		log.Printf("WARNING: config.json has unknown release channel %q, falling back to stable channel\n", channel)
-		return helper.ReleaseChannelStable
-	}
-}
diff --git a/updates/config.go b/updates/config.go
index f4aec988..62e3e124 100644
--- a/updates/config.go
+++ b/updates/config.go
@@ -123,7 +123,10 @@ func updateRegistryConfig(_ context.Context, _ interface{}) error {
 
 	if releaseChannel() != previousReleaseChannel {
 		previousReleaseChannel = releaseChannel()
-		helper.SetIndexes(registry, releaseChannel())
+		warning := helper.SetIndexes(registry, releaseChannel(), true)
+		if warning != nil {
+			log.Warningf("updates: %s", warning)
+		}
 		changed = true
 	}
 
diff --git a/updates/helper/indexes.go b/updates/helper/indexes.go
index 69b73d12..69443604 100644
--- a/updates/helper/indexes.go
+++ b/updates/helper/indexes.go
@@ -1,6 +1,10 @@
 package helper
 
 import (
+	"fmt"
+	"os"
+	"path/filepath"
+
 	"github.com/safing/portbase/updater"
 )
 
@@ -15,7 +19,7 @@ const (
 
 // SetIndexes sets the update registry indexes and also configures the registry
 // to use pre-releases based on the channel.
-func SetIndexes(registry *updater.ResourceRegistry, releaseChannel string) {
+func SetIndexes(registry *updater.ResourceRegistry, releaseChannel string, deleteUnusedIndexes bool) (warning error) {
 	usePreReleases := false
 
 	// Be reminded that the order is important, as indexes added later will
@@ -30,29 +34,50 @@ func SetIndexes(registry *updater.ResourceRegistry, releaseChannel string) {
 	})
 
 	// Add beta index if in beta or staging channel.
+	indexPath := ReleaseChannelBeta + ".json"
 	if releaseChannel == ReleaseChannelBeta ||
-		releaseChannel == ReleaseChannelStaging {
+		releaseChannel == ReleaseChannelStaging ||
+		(releaseChannel == "" && indexExists(registry, indexPath)) {
 		registry.AddIndex(updater.Index{
-			Path:       ReleaseChannelBeta + ".json",
+			Path:       indexPath,
 			PreRelease: true,
 		})
 		usePreReleases = true
+	} else if deleteUnusedIndexes {
+		err := deleteIndex(registry, indexPath)
+		if err != nil {
+			warning = fmt.Errorf("failed to delete unused index %s: %w", indexPath, err)
+		}
 	}
 
 	// Add staging index if in staging channel.
-	if releaseChannel == ReleaseChannelStaging {
+	indexPath = ReleaseChannelStaging + ".json"
+	if releaseChannel == ReleaseChannelStaging ||
+		(releaseChannel == "" && indexExists(registry, indexPath)) {
 		registry.AddIndex(updater.Index{
-			Path:       ReleaseChannelStaging + ".json",
+			Path:       indexPath,
 			PreRelease: true,
 		})
 		usePreReleases = true
+	} else if deleteUnusedIndexes {
+		err := deleteIndex(registry, indexPath)
+		if err != nil {
+			warning = fmt.Errorf("failed to delete unused index %s: %w", indexPath, err)
+		}
 	}
 
 	// Add support index if in support channel.
-	if releaseChannel == ReleaseChannelSupport {
+	indexPath = ReleaseChannelSupport + ".json"
+	if releaseChannel == ReleaseChannelSupport ||
+		(releaseChannel == "" && indexExists(registry, indexPath)) {
 		registry.AddIndex(updater.Index{
-			Path: ReleaseChannelSupport + ".json",
+			Path: indexPath,
 		})
+	} else if deleteUnusedIndexes {
+		err := deleteIndex(registry, indexPath)
+		if err != nil {
+			warning = fmt.Errorf("failed to delete unused index %s: %w", indexPath, err)
+		}
 	}
 
 	// Add the intel index last, as it updates the fastest and should not be
@@ -64,4 +89,19 @@ func SetIndexes(registry *updater.ResourceRegistry, releaseChannel string) {
 
 	// Set pre-release usage.
 	registry.SetUsePreReleases(usePreReleases)
+
+	return
+}
+
+func indexExists(registry *updater.ResourceRegistry, indexPath string) bool {
+	_, err := os.Stat(filepath.Join(registry.StorageDir().Path, indexPath))
+	return err == nil
+}
+
+func deleteIndex(registry *updater.ResourceRegistry, indexPath string) error {
+	err := os.Remove(filepath.Join(registry.StorageDir().Path, indexPath))
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return nil
 }
diff --git a/updates/main.go b/updates/main.go
index f9f26344..46e9ec92 100644
--- a/updates/main.go
+++ b/updates/main.go
@@ -114,7 +114,10 @@ func start() error {
 	}
 
 	// Set indexes based on the release channel.
-	helper.SetIndexes(registry, initialReleaseChannel)
+	warning := helper.SetIndexes(registry, initialReleaseChannel, true)
+	if warning != nil {
+		log.Warningf("updates: %s", warning)
+	}
 
 	err = registry.LoadIndexes(module.Ctx)
 	if err != nil {