Kids aged 16 and under will get free entry to the game with both sides thanking the other for the agreement.
The Brox have a free season ticket offer for 16 and under this campaign but prices in cup games have to be agreed by both clubs.
Broxburn boss Chris Townsley said: “We have to thank Blackburn for agreeing to the proposal.
“Our free season ticket offer for 16 and under has been a huge success this season and we’re glad we’re able to offer it for such an important game. It will hopefully benefit both teams and add a few to the gate.”
His Blackburn counterpart Jamie McCormick added: “Broxburn approached us about the idea and it’s something we were very keen to do.
“We both want as many fans as possible to be able to go to the game and hopefully this will help create a great atmosphere on the day.”
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