While developing a front end for an API (using React.js), my response is oddly being malformed.

users.jsx:

fetch("http://localhost:8080/users")
    .then((res) => {return res.json()})
    .then((result) => {
        console.log(result["id"])
// Should be something like 159985870458322944 but returns 159985870458322940 instead
// (the last digit has somehow turned from a 4 to a 0)
});

Checking the network tab in Chrome Devtools, the raw response shows a proper value for that key:

{
...
"id": 159985870458322944
...
}

What am I missing here?