This is a reference entry from MDN Web Docs. A full explanation with fixes has not been written yet.
ReferenceError: Super constructor may only be called once (V8-based)
ReferenceError: super() called twice in derived class constructor (Firefox)
ReferenceError: 'super()' can't be called more than once in a constructor. (Safari)
- Category
- ReferenceError
- Severity
- error
- Runtime
- both
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Source: MDN Web Docs. Data fetched 2026-09-25T01:48:37.274Z.