diff --git a/Misc/README.valgrind b/Misc/README.valgrind
index 8e480e9..157bdc3 100644
--- a/Misc/README.valgrind
+++ b/Misc/README.valgrind
@@ -12,6 +12,19 @@
   * Uncomment the lines in Misc/valgrind-python.supp that
     suppress the warnings for PyObject_Free and PyObject_Realloc
 
+If you want to use Valgrind more effectively and catch even more
+memory leaks, you will need to configure python --without-pymalloc.
+PyMalloc allocates a few blocks in big chunks and most object
+allocations don't call malloc, they use chunks doled about by PyMalloc
+from the big blocks.  This means Valgrind can't detect
+many allocations (and frees), except for those that are forwarded
+to the system malloc.  Note: configuring python --without-pymalloc
+makes Python run much slower, especially when running under Valgrind.
+You may need to run the tests in batches under Valgrind to keep
+the memory usage down to allow the tests to complete.  It seems to take
+about 5 times longer to run --without-pymalloc.
+
+
 Details:
 --------
 Python uses its own small-object allocation scheme on top of malloc,
@@ -21,7 +34,8 @@
 Starting with Python 2.3, PyMalloc is used by default.  You can disable
 PyMalloc when configuring python by adding the --without-pymalloc option.
 If you disable PyMalloc, most of the information in this document and
-the supplied suppressions file will not be useful.
+the supplied suppressions file will not be useful.  As discussed above,
+disabling PyMalloc can catch more problems.
 
 If you use valgrind on a default build of Python,  you will see
 many errors like: