Module build failed: SyntaxError: null is a reserved word

[pamuditha]

ERROR in ./src/scripts/structures/question.js
Module build failed: SyntaxError: null is a reserved word (242:66)

240 | return this.parse`
241 |

242 | ${ Header.bind(null, {heading: headingText, color: "white", null })}
| ^
243 | ${ Timer.bind(null, timerParams) }
244 |
245 |