News Release Correction To Second Quarter 2024 Sales Price per Carat

TORONTO, July 14, 2025 – Mountain Province Diamonds Inc. (“Mountain Province”, the “Company”) (TSX: MPVD) (OTC: MPVD) today announces a correction to its news release dated July 10, 2025 entitled “Mountain Province Announces Second Quarter 2025 Production and Sales Results, Details of Second Quarter 2025 Earnings Release, and Conference Call”.

The news release incorrectly referred to the average selling price for the second quarter ended June 30, 2023 and as a result incorrectly stated that the average selling price per carat, for the second quarter ended June 30, 2024 (“Q2 2024”) was CA$166 per carat (US$124 per carat). The correct average selling price for Q2 2024 was CA$102 per carat (US$74 per carat).

This correction does not change any other information reported in the July 10, 2025 news release and no other matters require correction.

About Mountain Province Diamonds Inc.

Mountain Province Diamonds is a 49% participant with De Beers Canada in the Gahcho Kué diamond mine located in Canada’s Northwest Territories. The Gahcho Kué Joint Venture property consists of several kimberlites that are actively being mined, developed, and explored for future development. The Company also controls more than 96,000 hectares of highly prospective mineral claims and leases surrounding the Gahcho Kué Mine that include an Indicated mineral resource for the Kelvin kimberlite and Inferred mineral resources for the Faraday kimberlites. Kelvin is estimated to contain 13.62 million carats (Mct) in 8.50 million tonnes (Mt) at a grade of 1.60 carats/tonne and value of US$63/carat. Faraday 2 is estimated to contain 5.45Mct in 2.07Mt at a grade of 2.63 carats/tonne and value of US$140/ct. Faraday 1-3 is estimated to contain 1.90Mct in 1.87Mt at a grade of 1.04 carats/tonne and value of US$75/carat. All resource estimations are based on a 1mm diamond size bottom cut-off.

For further information on Mountain Province Diamonds and to receive news releases by email, visit the Company’s website at www.mountainprovince.com.

For further information: FOR FURTHER INFORMATION, PLEASE CONTACT: Mark Wall, President and CEO, 151 Yonge Street, Suite 1100, Toronto, Ontario M5C 2W7, Phone: (416) 361-3562, E-mail: info@mountainprovince.com

NT4