Mr. Sean Roosen of Osisko Development reports

OSISKO DEVELOPMENT FILES EARLY WARNING REPORT REGARDING FALCO RESOURCES LTD.

Osisko Development Corp., on Oct. 17, 2025, acquired, indirectly through its wholly owned subsidiary, Barkerville Gold Mines Ltd. (BGM), 6.25 million units of Falco Resources Ltd. at a price of 32 cents per unit for an aggregate purchase price of $2-million, in connection with a bought deal private placement of 41,005,000 units completed by Falco. Each unit consisted of one common share of Falco and one-half of one common share purchase warrant of Falco.

Immediately prior to the offering, Osisko Development owned or controlled, indirectly through its wholly owned subsidiary, BGM, an aggregate of 48,675,240 common shares and 1.79 million warrants, representing approximately: (i) 16.0 per cent of the issued and outstanding common shares on a basic non-diluted basis; and (ii) 16.5 per cent of the issued and outstanding common shares on a partially diluted basis (assuming, for this purpose, only the exercise in full of the prior warrants).

As a result of and immediately following completion of the offering, Osisko Development owned or controlled, indirectly through its wholly owned subsidiary, BGM, an aggregate of 54,925,240 common shares and 4,915,000 warrants, representing approximately: (i) 15.9 per cent of the issued and outstanding common shares on a basic non-diluted basis; and (ii) 17.1 per cent of the issued and outstanding common shares on a partially diluted basis (assuming, for this purpose, only the exercise in full of the current warrants).

An early warning report in respect of Falco will be filed by Osisko Development with applicable Canadian securities regulatory authorities and will be available on SEDAR+ under Falco's issuer profile. To obtain copies of the early warning report filed by Osisko Development, please contact Philip Rabenok by telephone at 437-423-3644 or by e-mail at ir@osiskodev.com.

The securities were acquired by Osisko Development for investment purposes. Osisko Development, and its affiliates or any joint actors, may, from time to time and at any time, acquire additional common shares, and/or other equity, debt, or other securities or instruments of Falco, in the open market or otherwise, and reserves the right to dispose of any or all of its securities in the open market or otherwise at any time and from time to time, and to engage in similar transactions with respect to the Securities, the whole depending on market conditions, the business and prospects of Falco, and other relevant factors.

About Osisko Development Corp.

Osisko Development is a continental North American gold development company focused on past-producing mining camps located in mining-friendly jurisdictions with district-scale potential. The company's objective is to become an intermediate gold producer by advancing its flagship permitted 100-per-cent-owned Cariboo gold project, located in central British Columbia, Canada. Its project pipeline is complemented by the Tintic project in the historic East Tintic mining district in Utah, U.S., and the San Antonio gold project in Sonora, Mexico -- brownfield properties with significant exploration potential, extensive historical mining data, access to existing infrastructure and skilled labour. The company's strategy is to develop attractive, long-life, socially and environmentally responsible mining assets, while minimizing exposure to development risk and growing mineral resources.

We seek Safe Harbor.