diff --git a/Lib/shutil.py b/Lib/shutil.py
index 6688119..8ad0c64 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -523,7 +523,7 @@
 
     'base_name' is the name of the file to create, minus any format-specific
     extension; 'format' is the archive format: one of "zip", "tar", "ztar",
-    or "gztar".
+    "bztar" or "gztar".
 
     'root_dir' is a directory that will be the root directory of the
     archive; ie. we typically chdir into 'root_dir' before creating the