diff --git a/backend/internetarchive/internetarchive.go b/backend/internetarchive/internetarchive.go
index ce994c23c..ce021e35f 100644
--- a/backend/internetarchive/internetarchive.go
+++ b/backend/internetarchive/internetarchive.go
@@ -28,6 +28,7 @@ import (
 	"github.com/rclone/rclone/lib/bucket"
 	"github.com/rclone/rclone/lib/encoder"
 	"github.com/rclone/rclone/lib/pacer"
+	"github.com/rclone/rclone/lib/random"
 	"github.com/rclone/rclone/lib/rest"
 )
 
@@ -129,6 +130,7 @@ type IAFile struct {
 	// Source     string `json:"source"`
 	Mtime       string          `json:"mtime"`
 	RcloneMtime json.RawMessage `json:"rclone-mtime"`
+	UpdateTrack json.RawMessage `json:"rclone-update-track"`
 	Size        string          `json:"size"`
 	Md5         string          `json:"md5"`
 	Crc32       string          `json:"crc32"`
@@ -294,7 +296,7 @@ func (o *Object) Storable() bool {
 	return true
 }
 
-// SetModTime is not supported
+// SetModTime sets modTime on a particular file
 func (o *Object) SetModTime(ctx context.Context, t time.Time) (err error) {
 	bucket, reqDir := o.split()
 	if bucket == "" {
@@ -483,6 +485,7 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (_ fs.Objec
 		return nil, fs.ErrorCantCopy
 	}
 
+	updateTracker := random.String(32)
 	headers := map[string]string{
 		"x-archive-auto-make-bucket": "1",
 		"x-archive-queue-derive":     "0",
@@ -494,7 +497,8 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (_ fs.Objec
 		"x-archive-filemeta-crc32":   srcObj.crc32,
 		"x-archive-filemeta-size":    fmt.Sprint(srcObj.size),
 		// add this too for sure
-		"x-archive-filemeta-rclone-mtime": srcObj.modTime.Format(time.RFC3339Nano),
+		"x-archive-filemeta-rclone-mtime":        srcObj.modTime.Format(time.RFC3339Nano),
+		"x-archive-filemeta-rclone-update-track": updateTracker,
 	}
 
 	// make a PUT request at (IAS3)/:item/:path without body
@@ -515,7 +519,7 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (_ fs.Objec
 
 	// we can't update/find metadata here as IA will also
 	// queue server-side copy as well as upload/delete.
-	return f.waitFileUpload(ctx, trimPathPrefix(path.Join(dstBucket, dstPath), f.root, f.opt.Enc), f.getHashes(ctx, src), srcObj.size)
+	return f.waitFileUpload(ctx, trimPathPrefix(path.Join(dstBucket, dstPath), f.root, f.opt.Enc), updateTracker, srcObj.size)
 }
 
 // ListR lists the objects and directories of the Fs starting
@@ -660,12 +664,14 @@ func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, op
 	bucket, bucketPath := o.split()
 	modTime := src.ModTime(ctx)
 	size := src.Size()
+	updateTracker := random.String(32)
 
 	// Set the mtime in the metadata
 	// internetarchive backend builds at header level as IAS3 has extension outside X-Amz-
 	headers := map[string]string{
 		// https://github.com/jjjake/internetarchive/blob/2456376533251df9d05e0a14d796ec1ced4959f5/internetarchive/iarequest.py#L158
-		"x-amz-filemeta-rclone-mtime": modTime.Format(time.RFC3339Nano),
+		"x-amz-filemeta-rclone-mtime":        modTime.Format(time.RFC3339Nano),
+		"x-amz-filemeta-rclone-update-track": updateTracker,
 
 		// we add some more headers for intuitive actions
 		"x-amz-auto-make-bucket":     "1",    // create an item if does not exist, do nothing if already
@@ -712,7 +718,7 @@ func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, op
 	// or we have to wait for finish? (needs polling (frontend)/metadata/:item or scraping (frontend)/history/:item)
 	var newObj *Object
 	if err == nil {
-		newObj, err = o.fs.waitFileUpload(ctx, o.remote, o.fs.getHashes(ctx, src), size)
+		newObj, err = o.fs.waitFileUpload(ctx, o.remote, updateTracker, size)
 	} else {
 		newObj = &Object{}
 	}
@@ -782,18 +788,6 @@ func (o *Object) split() (bucket, bucketPath string) {
 	return o.fs.split(o.remote)
 }
 
-func (f *Fs) getHashes(ctx context.Context, src fs.ObjectInfo) map[hash.Type]string {
-	hashMap := map[hash.Type]string{}
-	for _, ty := range f.Hashes().Array() {
-		sum, err := src.Hash(ctx, ty)
-		if err != nil || sum == "" {
-			continue
-		}
-		hashMap[ty] = sum
-	}
-	return hashMap
-}
-
 func (f *Fs) requestMetadata(ctx context.Context, bucket string) (result MetadataResponse, err error) {
 	var resp *http.Response
 	// make a GET request to (frontend)/metadata/:item/
@@ -852,7 +846,7 @@ func (f *Fs) listAllUnconstrained(ctx context.Context, bucket string) (entries f
 	return entries, nil
 }
 
-func (f *Fs) waitFileUpload(ctx context.Context, reqPath string, newHashes map[hash.Type]string, newSize int64) (ret *Object, err error) {
+func (f *Fs) waitFileUpload(ctx context.Context, reqPath, tracker string, newSize int64) (ret *Object, err error) {
 	bucket, bucketPath := f.split(reqPath)
 
 	ret = &Object{
@@ -869,6 +863,10 @@ func (f *Fs) waitFileUpload(ctx context.Context, reqPath string, newHashes map[h
 			ret2, ok := ret2.(*Object)
 			if ok {
 				ret = ret2
+				ret.crc32 = ""
+				ret.md5 = ""
+				ret.sha1 = ""
+				ret.size = -1
 			}
 		}
 		return ret, nil
@@ -881,9 +879,6 @@ func (f *Fs) waitFileUpload(ctx context.Context, reqPath string, newHashes map[h
 	go func() {
 		isFirstTime := true
 		existed := false
-		oldMtime := ""
-		oldCrc32 := ""
-		unreliablePassCount := 0
 		for {
 			if !isFirstTime {
 				// depending on the queue, it takes time
@@ -908,10 +903,6 @@ func (f *Fs) waitFileUpload(ctx context.Context, reqPath string, newHashes map[h
 			if isFirstTime {
 				isFirstTime = false
 				existed = iaFile != nil
-				if iaFile != nil {
-					oldMtime = iaFile.Mtime
-					oldCrc32 = iaFile.Crc32
-				}
 			}
 			if iaFile == nil {
 				continue
@@ -925,38 +916,20 @@ func (f *Fs) waitFileUpload(ctx context.Context, reqPath string, newHashes map[h
 				return
 			}
 
-			hashMatched := true
-			for tt, sum := range newHashes {
-				if tt == hash.MD5 && !hash.Equals(iaFile.Md5, sum) {
-					hashMatched = false
-					break
-				}
-				if tt == hash.SHA1 && !hash.Equals(iaFile.Sha1, sum) {
-					hashMatched = false
-					break
-				}
-				if tt == hash.CRC32 && !hash.Equals(iaFile.Crc32, sum) {
-					hashMatched = false
+			fileTrackers, _ := listOrString(iaFile.UpdateTrack)
+			trackerMatch := false
+			for _, v := range fileTrackers {
+				if v == tracker {
+					trackerMatch = true
 					break
 				}
 			}
-			if !hashMatched {
+			if !trackerMatch {
 				continue
 			}
 			if !compareSize(parseSize(iaFile.Size), newSize) {
 				continue
 			}
-			if hash.Equals(oldCrc32, iaFile.Crc32) && unreliablePassCount < 60 {
-				// the following two are based on a sort of "bad" assumption;
-				// what if the file is updated immediately, before polling?
-				// by limiting hits of these tests, avoid infinite loop
-				unreliablePassCount++
-				continue
-			}
-			if hash.Equals(iaFile.Mtime, oldMtime) && unreliablePassCount < 60 {
-				unreliablePassCount++
-				continue
-			}
 
 			// voila!
 			retC <- struct {
@@ -1036,20 +1009,24 @@ func makeValidObject2(f *Fs, file IAFile, bucket string) *Object {
 	return makeValidObject(f, trimPathPrefix(path.Join(bucket, file.Name), f.root, f.opt.Enc), file, mtimeTime, size)
 }
 
-func (file IAFile) parseMtime() (mtime time.Time) {
-	// method 1: use metadata added by rclone
-	var rmArray []string
+func listOrString(jm json.RawMessage) (rmArray []string, err error) {
 	// rclone-metadata can be an array or string
 	// try to deserialize it as array first
-	err := json.Unmarshal(file.RcloneMtime, &rmArray)
+	err = json.Unmarshal(jm, &rmArray)
 	if err != nil {
 		// if not, it's a string
 		dst := new(string)
-		err = json.Unmarshal(file.RcloneMtime, dst)
+		err = json.Unmarshal(jm, dst)
 		if err == nil {
 			rmArray = []string{*dst}
 		}
 	}
+	return
+}
+
+func (file IAFile) parseMtime() (mtime time.Time) {
+	// method 1: use metadata added by rclone
+	rmArray, err := listOrString(file.RcloneMtime)
 	// let's take the first value we can deserialize
 	for _, value := range rmArray {
 		mtime, err = time.Parse(time.RFC3339Nano, value)