TypeScript definition for ValueType not found

When generating JavaScript/TypeScript for a very simple C# struct:

[JSExport] public struct Interface { ...

In the .d.ts file following is generated:

import './System.Collections';
import './System.Runtime';

export class Interface extends ValueType {...

ValueType is unknown to the typescript compiler:

Where is the TypeScript definition for ValueType or how can I avoid the TypeScript compiler error? Obviously there is no issue during runtime.

Is this an issue or do I overlook something?

Reproduce the simple C# struct with [JSExport] and inspect the generated .d.ts file, especially the Interface declaration and its ValueType reference. Check how the TypeScript compiler resolves the generated imports and determine whether the completed work should provide a ValueType definition or document a way to avoid the compiler error.