diff --git a/README.md b/README.md
index 55bab4d..ff9f715 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ API calls.
     --temp-files-dir <dir> : where to store temporary files created when compressing (defaults to current working directory)
     --write-version <version> : Force write version file format (default 1)
     --chunk-min-size <bytes> : v1 file format minimum chunk size (default 4194304 or 4MiB)
+    --pre-sort-files : pre-sorts files by size so that the first file is the largest
     -- : specifies remaining arguments are files to archive/extract
     If creating archive file, remaining args specify files to archive.
     If extracting archive file, remaining args specify files to extract.