diff --git a/Misc/SpecialBuilds.txt b/Misc/SpecialBuilds.txt
index 17cfaec..a30801f 100644
--- a/Misc/SpecialBuilds.txt
+++ b/Misc/SpecialBuilds.txt
@@ -141,6 +141,7 @@
 sanity checks inside "#ifdef Py_DEBUG" blocks.
 ---------------------------------------------------------------------------
 COUNT_ALLOCS                                            introduced in 0.9.9
+                                             partly broken in 2.2 and 2.2.1
 
 Each type object grows three new members: