Exhibit (m)(1)(a)

AMENDMENT TO

JANUS DETROIT STREET TRUST

DISTRIBUTION AND SHAREHOLDER SERVICING PLAN

THIS AMENDMENT is made this 16^th day of July 2026, by and among JANUS DETROIT STREET TRUST, a Delaware statutory trust (the “Trust”), Janus Henderson Distributors US LLC, (“JDL”), and ALPS Distributors, Inc., ("ALPS"), regarding the funds listed in Exhibit A (each, a “Fund” and together, the “Funds”).

WITNESSETH:

WHEREAS, JDL, ALPS, and the Trust, are parties to the Distribution and Shareholder Servicing Plan dated September 12, 2018 (the “Plan”);

WHEREAS, the parties desire to amend the Plan as set forth in greater detail below;

WHEREAS, pursuant to Section 7 of the Plan, the Plan may be amended by the parties only if such amendment is approved by the Board, including a majority of the directors who are not interested persons of ALPS, JDL, or of the Trust and is in writing and signed by the parties to the Plan; and

WHEREAS, Exhibit A is hereby replaced with the attached Exhibit A to reflect the addition of Janus Henderson International Core Alpha ETF.

NOW, THEREFORE, in consideration of the premises and of the mutual agreements set forth below, the parties agree to amend the Plan as follows:

1.       The parties acknowledge that the Plan, as amended, remains in full force and effect as of the date of this Amendment, and that this Amendment, together with the Plan, contains the entire understanding and the full and complete agreement of the parties and supersedes and replaces any prior understandings and agreements among the parties respecting the subject matter hereof.

2.       This Amendment may be contemporaneously executed in two or more counterparts, each of which shall be deemed an original but all of which together shall constitute one and the same instrument.

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IN WITNESS WHEREOF, the parties have caused their duly authorized officers to execute this Amendment as of the date and year first above written.

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EXHIBIT A TO THE

DISTRIBUTION AND SHAREHOLDER SERVICING PLAN

Janus Detroit Street Trust

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