Bug #3951: Py_USING_MEMORY_DEBUGGER should not be enabled by default.
diff --git a/Misc/NEWS b/Misc/NEWS
index 37bb634..5d2a267 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
Core and Builtins
-----------------
+- Bug #3951: Py_USING_MEMORY_DEBUGGER should not be enabled by default.
+
Library
-------
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index fc5ccf7..d1586c2 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -677,8 +677,8 @@
/* This is only useful when running memory debuggers such as
* Purify or Valgrind. Uncomment to use.
*
- */
#define Py_USING_MEMORY_DEBUGGER
+ */
#ifdef Py_USING_MEMORY_DEBUGGER