diff --git a/docs/source/command_line.rst b/docs/source/command_line.rst
index 727d500e2d4d..4e954c7c2ccb 100644
--- a/docs/source/command_line.rst
+++ b/docs/source/command_line.rst
@@ -789,6 +789,17 @@ in error messages.
     useful or they may be overly noisy. If ``N`` is negative, there is
     no limit. The default limit is 200.
 
+.. option:: --force-uppercase-builtins
+
+    Always use ``List`` instead of ``list`` in error messages,
+    even on Python 3.9+.
+
+.. option:: --force-union-syntax
+
+    Always use ``Union[]`` and ``Optional[]`` for union types
+    in error messages (instead of the ``|`` operator),
+    even on Python 3.10+.
+
 
 .. _incremental: