Chinese infrastructure spending bounced back in June, lending a welcome hand to factories as they battle the effects of slowing growth. But the boost may not last long.

China’s fiscal room for maneuver in the second half of the year looks limited, meaning that monetary policy—and off-budget spending—may once again need to take up the slack.

Following three months of slowing growth, infrastructure investment increased around 4% compared with the same month of 2018, according to research firm Oxford Economics.

That was no accident—it was supported by a huge surge in local government bond issuance. Local governments issued 900 billion yuan ($130 billion) of official debt in June, nearly three times May’s figure and the highest since mid-2016, when China’s last major stimulus was in full swing.

The jump is probably a one-off, however. Local governments have already used up around 70% of their 2019 new debt quota set by Beijing. The central government is unlikely to take the unusual step of lifting the ceiling midyear, as it could be interpreted as a green light for a new round of dubious projects.