# E4124

The constructor is ambiguous: it may come from multiple types.

## Erroneous example

```{literalinclude} /sources/error_codes/4124_error/top.mbt
:language: moonbit
```

## Suggestion

Add `T::` before the constructor:

```{literalinclude} /sources/error_codes/4124_fixed/top.mbt
:language: moonbit
```