Costco is hiking its annual membership fees in Canada and the U.S., following a weaker than expected holiday shopping season.

The fee increases will take effect on June 1, impacting approximately 35 million members who pay for the right to shop at the wholesale warehouse retailer.

Canada and U.S. “goldstar” (individual), business and business add-on members will see their annual dues jump from $55 to $60, the company said in a media release Thursday. The cost of executive membership on both sides of the border will increase from $110 to $120.

The Washington-based retailer operates 94 of its 728 warehouses in Canada.

Costco’s 87 million-strong global membership is the company’s profit driver. Membership fees accounted for about 72 per cent of the Costco’s operating income in 2016, according to the company’s latest annual filing.