China’s exports ticked up 3.5% in April compared to a year earlier in US dollar terms, according to customs data released by Beijing on Thursday.

That was much stronger than expected: Analysts polled by Refinitiv expected a 15.7% decline. The increase also reversed March’s 6.6% drop.

Last month’s boost might have been aided by a backlog of orders that were cleared as factories reopened from coronavirus lockdown measures, according to Julian Evans-Pritchard, senior China economist for Capital Economics. Business was shut down for a significant chunk of the first quarter as the virus forced China’s economy to a near-halt.

Evans-Pritchard warned in a Thursday research note, though, that the uptick likely won’t last.

Exporters are “unlikely to be immune from the sharp slowdown in global activity for long,” he said.

Imports for April, meanwhile, were weak as the rest of the world contended with the pandemic. Data showed Thursday that imports fell 14.2% in April, worse than the 11.2% decline that analysts surveyed by Refinitiv expected. Imports fell 0.9% in March.

The sharp deterioration in activity among China’s key trade partners will probably result in much weaker exports in May, according to Evans-Pritchard.

Meanwhile, the threat of additional US tariffs on Chinese goods shouldn’t be ignored, he said. Trade tensions are once again brewing: US President Donald Trump hinted late last week that the United States could punish China with new tariffs because of the coronavirus outbreak.