diff --git a/pep-0455.txt b/pep-0455.txt
index 7907c8e8e..0a2789731 100644
--- a/pep-0455.txt
+++ b/pep-0455.txt
@@ -113,6 +113,12 @@ together with the corresponding value::
 The method name ``getitem()`` mirrors the standard ``popitem()`` method
 on mutable mappings.
 
+Getting the transformation function
+-----------------------------------
+
+TransformDict has a simple read-only property ``transform_func`` which
+gives back the transformation function.
+
 
 Alternative proposals and questions
 ===================================