Error in generated code: Interface declaration cannot have 'implements' clause


I’m generating Typescript code but it looks like the generated code is not valid. I get the error "Interface declaration cannot have 'implements' clause." from the following code:

    interface GetPingRequest implements IReturn<PingModel> {
        ping?: string;

I’m using V4.0.48.
Is this a new Typescript syntax? Perhaps I need to use a different version of Typescript.

This should already be fixed in v4.0.49 on MyGet