Is a virtual destructor needed for your Interface, if you always store it in a shared_ptr?

Since boost::/std::shared_ptr have the advantage of type-erasing their deleter, you can do nice things like

#include <memory>

typedef std::shared_ptr<void> gc_ptr;

int main(){
  gc_ptr p1 = new int(42);
  gc_ptr p2 = new float(3.14159);
  gc_ptr p3 = new char('o');
}

And this will correctly delete all pointer thanks to the correct deleter being saved.

If you ensure that every implementation of your interface always gets created with shared_ptr<Interface> (or make_shared<Interface>), do you actually need a virtual destructor? I would declare it virtual anyways, but I just want to know, since shared_ptr will always delete the type it was initialized with (unless another custom deleter is given).