Costa Rica is considering levying a $15 tax on international passengers arriving in the country, causing the airline industry, represented by IATA, to cry foul.

The law currently being debated would tax arriving passengers but would not apply to Costa Ricans. IATA, in a letter to the minister of tourism, says the proposed tax could be perceived as discriminatory. Furthermore, IATA argues that the tax could be a disincentive for travelers to visit Costa Rica. But this tax could unravel years of work by turning visitors away and sending the wrong signals, IATA says.

Tourism will account for 13.5% of Costa Rica’s GDP this year, which suggests how important the sector is to the country’s economy, IATA says.

The proposed tax could siphon off passengers to other countries in the region. It also runs contrary to Costa Rica’s agenda to increase tourism to the country. Much like a tax on tobacco, the proposed tax will penalize tourism, and the government will see the collection of the tax decrease as tourism diminishes.

Argentina last month began levying a reciprocal tax on citizens of countries that require visas of Argentine nationals. IATA objected to that tax for much the same reason it objects to Costa Rica’s planned tax.