[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Type](https://evolu.dev/docs/api-reference/common/Type) › DiscriminatedUnionMemberError

```ts
type DiscriminatedUnionMemberError<Issue> = [Issue] extends [never]
  ? never
  : TypeError<"DiscriminatedUnion"> & {
      reason: Issue;
    };
```

Defined in: [packages/common/src/Type.ts:12592](https://github.com/evoluhq/evolu/blob/f0109fb501a593010e858e39248dde1200eeb2d7/packages/common/src/Type.ts#L12592)

An error returned by the member selected by [discriminatedUnion](https://evolu.dev/docs/api-reference/common/Type/functions/discriminatedUnion).