opdatabin.readBigUInt64LE is not a function

[StormCh]

info: Unlocking vault...
Password:
/home/christian/Schreibtisch/onepass-master/opvault.js:112
var plaintextlen = Number(opdatabin.readBigUInt64LE(8));
^

TypeError: opdatabin.readBigUInt64LE is not a function
at decryptOpdata (/home/christian/Schreibtisch/onepass-master/opvault.js:112:41)
at decryptMainKeys (/home/christian/Schreibtisch/onepass-master/opvault.js:158:21)
at Object.exports.unlockKeychain (/home/christian/Schreibtisch/onepass-master/opvault.js:192:16)
at startDaemon (/home/christian/Schreibtisch/onepass-master/onepass.js:23:13)
at Object. (/home/christian/Schreibtisch/onepass-master/onepass.js:19:5)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)

[paulsc]

You're probably running an old node version. Try upgrading.