Exhibit 99.7

To:

Securities Regulatory Authorities

B. C. Securities Commission

Alberta Securities Commission

Saskatchewan Financial Services Commission

Manitoba Securities Commission

Ontario Securities Commission

L’Autorité des marchés financiers

Nova Scotia Securities Commission

New Brunswick Securities Commission

Prince Edward Island Securities Office

Securities Commission of Newfoundland and Labrador

Toronto Stock Exchange

CONSENT of AUTHOR

I, William Roscoe, do hereby consent to the public filing of the technical report titled “Prefeasibility Study Report for the Wheeler River Uranium Project, Saskatchewan, Canada” (the Technical Report) with an effective date of September 24, 2018 by Denison Mines Corp.

I also consent to any extracts from or a summary of the Technical Report under the National Instrument 43-101 disclosure of Denison, in the press release of Denison Mines Corp. dated September 24, 2018 (the “Press Release”).

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

Dated this 22nd day of October, 2018.

“Signed”

William Roscoe, P.Eng.

Principal Geologist

RPA 55 University Ave. Suite 501 | Toronto, ON, Canada M5J 2H7 | T +1 (416) 947 0907 www.rpacan.com