Exhibit 99.8 

To:

British Columbia Securities Commission, as Principal Regulator

Alberta Securities Commission

Financial and Consumer Affairs Authority of Saskatchewan

The Manitoba Securities Commission

Ontario Securities Commission

Autorité des marchés financiers

Securities, Financial and Consumer Services Commission (New Brunswick)

Nova Scotia Securities Commission

Office of the Superintendent of Securities (Prince Edward Island)

Office of the Superintendent of Securities Service Newfoundland and Labrador

Toronto Stock Exchange

CONSENT OF AUTHOR

I, Alan Sexton, M.Sc., P.Geo., do hereby consent to the public filing of the technical report titled “Technical Report with an Updated Mineral Resource Estimate for the Waterbury Lake Property, Northern Saskatchewan, Canada” (the “Technical Report”) with an effective date of December 21, 2018 by Denison Mines Corp. (“Denison”).

I also consent to the use of any extracts from, or the summary of, the Technical Report in the management’s discussion and analysis for the three and nine months ended September 30, 2018 dated November 9, 2018 (the “MDA”) and in the related press release of Denison dated November 12, 2018 (the “Press Release”, and with the MDA, the “Disclosure”).

I certify that I have read the Disclosure and that it fairly and accurately represents the information in the sections of the Technical Report for which I am responsible.

Dated this 21st day of December, 2018.

(Signed and Sealed) “Alan Sexton”

Alan Sexton, M.Sc., P.Geo.