Canada’s merchandise trade with the rest of the world slowed in April on planned maintenance shutdowns in the oil sands.

Exports rose just 0.6% in April, after surging 7% and 3.8% the previous two months, Statistics Canada reported on Tuesday. Export volumes were down 2.1%. Imports rose 1.9% in nominal terms, while dropping 0.4% in terms of volumes.

The nation’s trade surplus narrowed to C$1.5 billion in April, from C$2.3 billion a month earlier. Trade in consumer goods led gains in both imports and exports.

Economists were anticipating the surplus would widen to C$2.8 billion in April, from C$2.5 billion initially reported in March.

Rising oil prices over the past year have helped the nation swing into recurring surpluses for the first time since 2014. In the first four months of 2022, the nation recorded a cumulative C$9.5 billion of surpluses.

But the strong revenue from shipments abroad have masked lower volumes, particularly in the energy sector. Since the start of the year, the nation’s export volumes are down 4.9% even as the value of shipments have risen by 13%.

In April, exports of crude oil fell 14.3% on lower volumes. That was almost fully offset by rising shipments of natural gas and coal, the statistics agency said.

The nation’s trade deficit in services widened in April to C$1.3 billion from C$796 million in March, as Canadians increased their travel abroad.