Exhibit 1(xx)

                              JANUS INVESTMENT FUND

                            AMENDMENT TO CERTIFICATE
                     REDESIGNATING JANUS MID CAP VALUE FUND

     The undersigned, being the duly elected and qualified Secretary of Janus
Investment Fund, a trust with transferable shares under the laws of
Massachusetts (the "Trust") authorized to establish one or more series or funds,
which was organized pursuant to an Agreement and Declaration of Trust dated
February 11, 1986 (as amended and restated March 18, 2003, and further amended
and restated to date, the "Declaration"), DOES HEREBY CERTIFY that:

     The Certificate Redesignating Janus Mid Cap Value Fund dated December 23,
     2008 and filed on December 23, 2008, is hereby amended to revise the last
     line in Paragraph one to read "Mid Cap Value Fund, such redesignation to be
     effective December 31, 2008."

     IN WITNESS WHEREOF, the undersigned has set her hand and seal this 30th day
of December, 2008.


                                          /s/ Stephanie Grauerholz-Lofton
                                          --------------------------------------
                                          Stephanie Grauerholz-Lofton, Secretary



STATE OF COLORADO             )
                              ) ss.
CITY AND COUNTY OF DENVER     )

     BEFORE ME, the undersigned authority, on this day personally appeared
Stephanie Grauerholz-Lofton, Secretary of Janus Investment Fund, who, being by
me first duly sworn, stated on her oath that the foregoing document is true and
correct and that she executed the same for the purposes and consideration
therein expressed and in the capacity therein stated.

     GIVEN UNDER MY HAND AND SEAL OF OFFICE this 30th day of December, 2008.

My Commission Expires:


06/08/11                                  /s/ Lynn D. Williams
                                          --------------------------------------
                                          Notary Public

                                          [Notary Seal]


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