December 13, 2018

First Trust Exchange-Traded Fund IV
120 East Liberty Drive, Suite 400
Wheaton, Illinois 60187


    Re: Fee Wavier Extension Letter for First Trust TCW Unconstrained Plus Bond
        ETF (the "Fund"), a series of First Trust Exchange-Traded Fund VIII (the
        "Trust")

Ladies and Gentlemen:

    Reference is hereby made to that certain Fee Waiver Agreement between the
Trust, on behalf of the Fund, and First Trust Advisors L.P., the investment
advisor to the Fund (the "Advisor"), dated as of May 28, 2018 (the "Agreement").
Capitalized terms used herein but not otherwise defined shall have the meanings
attributed to them in the Agreement.

    The Advisor hereby agrees to waive investment management fees otherwise
payable to it by the Fund in the amount of 0.10% of the Fund's average daily net
assets (the "Waived Amount") and that the Waiver Term shall continue until
December 31, 2019. The parties hereby acknowledge that with the exception of the
Waived Amount and the Waiver Term, the Agreement shall remain in full force and
effect.

                                          Very Truly Yours,

                                          FIRST TRUST ADVISORS L.P.


                                          /s/ James M. Dykas
                                          --------------------------------------
                                          James M. Dykas
                                          Chief Financial Officer



AGREED AND ACKNOWLEDGED:

First Trust Exchange-Traded Fund IV,
on behalf of First Trust Enhanced
Short Maturity ETF


/s/ Donald P. Swade
--------------------------------------
Donald P. Swade
Treasurer, Chief Financial Officer and
Chief Accounting Officer