[plt-scheme] Let-syntax not transparent to top-level defines

I am writing a macro that expands to a let-syntax expression, 
which binds #%app. This works fine when it's wrapped around most 
expressions. When you wrap it around a group of top level 
defines, however, it introduces a new lexical scope, rather than 
being transparent to them. I would like to have something like 
the following at the top level:

(with-tracing
   (define (foo bar)
     (+ 1 bar))
   (define (baz quux)
     (* 10 quux)))

and have those defines apply at the top level with #%app rebound 
to the right thing. I also need this to work within the top 
level of a module. Is there any way for me to do something like 
this?