@@ -27,6 +27,7 @@ type Fetcher struct {
 	options *Options
 	log     *log.Logger
 	updater events.Listener
+	current uint64
 }
 
 type Options struct {
@@ -60,6 +61,7 @@ return errors.WithMessage(err, "could not fetch file")
 		}
 	}
 
+	f.current = run
 	err = renameio.Symlink(runID, filepath.Join(f.options.Root, "current"))
 	if err != nil {
 		return errors.WithMessage(err, "could not create/update symlink")
@@ -88,6 +90,41 @@
 	return nil
 }
 
+func (f *Fetcher) CleanOldRevisions() error {
+	contents, err := os.ReadDir(f.options.Root)
+	if err != nil {
+		return errors.WithMessage(err, "could not read root directory")
+	}
+	for _, file := range contents {
+		name := file.Name()
+		if name == "current" {
+			continue
+		}
+		if numericFilename.MatchString(name) {
+			v, err := strconv.ParseUint(name, 10, 64)
+			if err != nil {
+				return errors.WithMessagef(err, "could not parse numeric filename %s", name)
+			}
+			if v < f.current-1 {
+				err := os.RemoveAll(filepath.Join(f.options.Root, name))
+				if err != nil {
+					return errors.WithMessage(err, "could not remove folder")
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (f *Fetcher) cleanOldRevisionsAsync() {
+	go func() {
+		if err := f.CleanOldRevisions(); err != nil {
+			f.log.Warn("error cleaning up old revisions", "error", err)
+		}
+	}()
+}
+
 func (f *Fetcher) getFile(runID, basename string) error {
 	filename := filepath.Join(f.options.Root, runID, basename)
 	url := f.options.FetchURL.JoinPath(runID, basename).String()
@@ -130,12 +167,12 @@ target, err := os.Readlink(filepath.Join(f.options.Root, "current"))
 	if err != nil && errors.Is(err, fs.ErrNotExist) {
 		return 0, errors.WithMessage(err, "could not stat current link")
 	}
-	runID, err := strconv.ParseUint(target, 10, 64)
+	f.current, err = strconv.ParseUint(target, 10, 64)
 	if err != nil {
 		return 0, errors.WithMessagef(err, "unexpected symlink target (current -> %s)", target)
 	}
 
-	return runID, nil
+	return f.current, nil
 }
 
 func (f *Fetcher) initialiseStorage() (uint64, error) {
@@ -150,6 +187,7 @@ f.log.Warn("could not get current version", "error", err)
 	}
 
 	f.log.Debug("versions", "current", current, "latest", latest)
+	defer f.cleanOldRevisionsAsync()
 
 	if latest > current {
 		err = f.getArtefacts(latest)