<Page>

                                                                   EXHIBIT 32.01

                           SECTION 1350 CERTIFICATIONS

In connection with this quarterly report of John W. Henry & Co./Millburn L.P.
(the "Company") on Form 10-Q for the period ended June 30, 2005 as filed with
the Securities and Exchange Commission on the date hereof (this "Report"), I,
Robert M. Alderman, certify, pursuant to 18 U.S.C. Section 1350, as adopted
pursuant of the Sarbanes-Oxley Act of 2002, that:

1. This Report fully complies with the requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and

2. The information contained in this Report fairly presents, in all material
respects, the financial condition and results of operations of the Company.


Date: August 12, 2005
- -----------------------

By /s/ ROBERT M. ALDERMAN
   ----------------------
Robert M. Alderman
Chief Executive Officer, President and Manager
(Principal Executive Officer)