Israel has set a higher threshold for any future vote on ceding parts of Jerusalem to the Palestinians, who want the eastern part of the city for a future independent state.
The amendment passed by the Israeli parliament to existing legislation raised from 61 to 80 the number of votes that would be required in the 120-seat Knesset to approve any proposal to hand over part of the city to "a foreign party".
The amendment, long in the legislative pipeline, comes less than a month after US President Donald Trump angered the Palestinians, Middle East leaders and world powers by recognising Jerusalem as Israel's capital.
US negotiations between Israel and the Palestinians have been frozen since 2014 but, if ever resumed, a special Israeli parliament majority to approve handing over parts of Jerusalem could complicate efforts to reach a peace accord.
Trump's decision touched off protests in the region and the Palestinians have said Washington can no longer serve as a peace broker. A US bid to revive negotiations, led by the president's adviser and son-in-law, Jared Kushner, has so far shown no progress.
Palestinian officials were not immediately available for comment on the new amendment, which passed by a vote of 64 to 52.
The status of Jerusalem is one of the most sensitive issues in the decades-old Israeli-Palestinian conflict.