UPS has reached a contract agreement with its 340,000-person strong union today, averting a strike that had the potential to disrupt logistics nationwide for businesses and households alike.

The Teamsters called the tentative agreement “historic” and “overwhelmingly lucrative.” It includes, among other benefits, higher wages and air conditioning in delivery trucks.

Members of the Teamsters, angered by a contract they say was forced on them five years ago by union leadership, clashed with UPS over pay as profits for the delivery company soared in recent years. Union leadership was upended last year with the election of Sean O’Brien, a vocal critic of the union president who signed off on that contract, James Hoffa, the son of the famous Teamsters firebrand.

The two side reached a tentative agreement early on safety issues, including equipping more trucks with air conditioning equipment. Under the agreement, UPS said it would add air conditioning to U.S. small delivery vehicles purchased after January 1, 2024.

But a two-tier wage system remained a sticking point. The Teamsters called it “unfair,” and that is ended under the new agreement.

Profits at UPS have grown more than 140% since the last contract was signed as the arrival of a deadly pandemic drastically transformed the manner in which households get what they need.

Unionized workers argued that were the ones shouldering growth at the Atlanta company and appeared dead set on righting what they saw as a bad contract.

Member voting begins Aug. 3 and concludes Aug. 22.

UPS has the largest private-sector contract with workers in North America and the last breakdown in labor talks a quarter century ago led to a 15-day walkout by 185,000 workers that crippled the company.