diff --git a/cmd/rmr.go b/cmd/rmr.go
index 91240b07e9f6..2ad1090e03b6 100644
--- a/cmd/rmr.go
+++ b/cmd/rmr.go
@@ -47,7 +47,7 @@ $ juicefs rmr /mnt/jfs/foo`,
                                 Name:  "threads",
 				Aliases: []string{"p"},
                                 Value: 50,
-                                Usage: "number of threads for delete jobs (appropriate value)",
+                                Usage: "number of threads for delete jobs (value from 2 to 255)",
                         },
 		},
 	}
@@ -71,15 +71,12 @@ func openController(dpath string) (*os.File, error) {
 func rmr(ctx *cli.Context) error {
 	setup(ctx, 1)
 	var flag uint8
-	var numThreads int
+	var numThreads uint8
 
-	numThreads = ctx.Int("threads")
+	numThreads = uint8(ctx.Int("threads"))
 	if numThreads < 2 {
 		numThreads = 2
 	}
-	if numThreads > 127 {
-		numThreads = 127
-	}
 	if ctx.Bool("skip-trash") {
 		if os.Getuid() != 0 {
 			logger.Fatalf("Only root can remove files directly")
@@ -112,7 +109,8 @@ func rmr(ctx *cli.Context) error {
 		wb.Put64(inode)
 		wb.Put8(uint8(len(name)))
 		wb.Put([]byte(name))
-		wb.Put8(flag + uint8(numThreads * 2))
+		wb.Put8(flag)
+		wb.Put8(numThreads)
 		_, err = f.Write(wb.Bytes())
 		if err != nil {
 			logger.Fatalf("write message: %s", err)
diff --git a/pkg/meta/utils.go b/pkg/meta/utils.go
index 1353d59077df..49f8d33d2e23 100644
--- a/pkg/meta/utils.go
+++ b/pkg/meta/utils.go
@@ -352,6 +352,10 @@ func (m *baseMeta) RemoveEx(ctx Context, parent Ino, name string, skipTrash bool
 	}
 	if numThreads <= 0 {
 		numThreads = 50
+	} else if numThreads < 2 {
+		numThreads = 2
+	} else if numThreads > 255 {
+		numThreads = 255
 	}
 	concurrent := make(chan int, numThreads)
 	return m.emptyEntry(ctx, parent, name, inode, skipTrash, count, concurrent)
diff --git a/pkg/vfs/internal.go b/pkg/vfs/internal.go
index e0dfb7f1b54c..87e86b791bcf 100644
--- a/pkg/vfs/internal.go
+++ b/pkg/vfs/internal.go
@@ -298,22 +298,17 @@ func (v *VFS) handleInternalMsg(ctx meta.Context, cmd uint32, r *utils.Buffer, o
 		inode := Ino(r.Get64())
 		name := string(r.Get(int(r.Get8())))
 		var skipTrash bool
-		var numThreads int = 50
+		var numThreads uint8 = 50
 		if r.HasMore() {
-			numThreads = int(r.Get8())
-			skipTrash = numThreads&1 != 0
-			numThreads = numThreads / 2
-			if numThreads == 0 {
-				numThreads = 50
-			}
-			if numThreads < 2 {
-				numThreads = 2
+			skipTrash = r.Get8()&1 != 0
+			if r.HasMore() {
+				numThreads = r.Get8()
 			}
 		}
 		var count uint64
 		var st syscall.Errno
 		go func() {
-			st = v.Meta.RemoveEx(ctx, inode, name, skipTrash, numThreads, &count)
+			st = v.Meta.RemoveEx(ctx, inode, name, skipTrash, int(numThreads), &count)
 			if st != 0 {
 				logger.Errorf("remove %d/%s: %s", inode, name, st)
 			}