diff --git a/doc/assert.txt b/doc/assert.txt
index 191cd1a66..04a1023a3 100644
--- a/doc/assert.txt
+++ b/doc/assert.txt
@@ -160,6 +160,15 @@ easy to rewrite the assertion and avoid any trouble::
 
 All assert debugging can be turned off by passing ``--assertmode=off``.
 
+.. versionadded:: 2.1
+
+   Add assert rewriting as an alternate debugging technique.
+
+.. versionchanged:: 2.1
+
+   Introduce the ``--assertmode`` option. Deprecate ``--no-assert`` and
+   ``--nomagic``.
+
 ..
     Defining your own comparison
     ----------------------------------------------