diff --git a/weed/shell/command_volume_fsck.go b/weed/shell/command_volume_fsck.go
index c79b062f7..584ce722b 100644
--- a/weed/shell/command_volume_fsck.go
+++ b/weed/shell/command_volume_fsck.go
@@ -69,7 +69,7 @@ func (c *commandVolumeFsck) Do(args []string, commandEnv *CommandEnv, writer io.
 	findMissingChunksInFilerPath := fsckCommand.String("findMissingChunksInFilerPath", "/", "used together with findMissingChunksInFiler")
 	findMissingChunksInVolumeId := fsckCommand.Int("findMissingChunksInVolumeId", 0, "used together with findMissingChunksInFiler")
 	applyPurging := fsckCommand.Bool("reallyDeleteFromVolume", false, "<expert only!> after detection, delete missing data from volumes / delete missing file entries from filer")
-	c.forcePurging = fsckCommand.Bool("forcePurging", false, "delete missing data from volumes in one replica")
+	c.forcePurging = fsckCommand.Bool("forcePurging", false, "delete missing data from volumes in one replica used together with applyPurging")
 	purgeAbsent := fsckCommand.Bool("reallyDeleteFilerEntries", false, "<expert only!> delete missing file entries from filer if the corresponding volume is missing for any reason, please ensure all still existing/expected volumes are connected! used together with findMissingChunksInFiler")
 	tempPath := fsckCommand.String("tempPath", path.Join(os.TempDir()), "path for temporary idx files")