On March 12, customers can get a free small Thin Mints Frosty with any purchase in the mobile app at participating Wendy’s restaurants nationwide, according to the Ohio-based burger chain. The one-day offer can also be redeemed online, Wendy’s said.

UNDATED (WKRC) - Wendy's iconic Frosty is about to get a makeover. The fast-food chain announced Thursday that it will soon introduce new ways to customize the beloved sweet treat.

In honor of National Girl Scout Day on March 12 and St. Patrick's Day on March 17, Wendy's is offering free Thin Mints Frostys and Fries this week, respectively. Customers can grab the deals through the Wendy's app or website.

This new Frosty drop was perfectly timed for National Girl Scout Cookie season, and now you can snag one for free. In honor of National Girl Scout Day on March 12, Wendy’s is giving away free small Thin Mints Frosty treats with any purchase—exclusively through the Wendy’s app.

And what goes better with a Frosty? How about fries? Now through March 17, St. Patrick’s Day, Wendy’s is giving away free fries with a $5 purchase and drink. Again, you’ll need the app to claim the offer. As always, the deals are subject to a location’s participation, USA Today reported.

Related: Fans Say Wendy’s Is ‘On A Roll’ With 'Phenomenal' New Frosty Treats: 'Now We're Talking' To coincide with National Girls Scouts Day, the beloved fast food chain will be giving away free small Thin Mints Frostys all day long on March 12.