Owin Default Files

I just came around the problem that I wanted to serve static files via Owin. Therefore I added the NuGet package Microsoft.Owin.StaticFiles, and added the following to my Startup class:

app.UseStaticFiles();
app.UseDefaultFiles(new DefaultFilesOptions 
  { 
    DefaultFileNames = new[] { "index.html" } 
  });

With this, I was able to serve static files, but the default document didn’t work. I always got a HTTP 404 response. Even though I saw the access to the file in the Process Monitor. Finally, I found the solution in one of the answers to a question of Stack Overflow. I had to call UseDefaultFiles first! Before UseStaticFiles:

app.UseDefaultFiles(new DefaultFilesOptions 
  { 
    DefaultFileNames = new[] { "index.html" } 
  });
app.UseStaticFiles();