I have colleagues on the other hand who thing that aeronautical engineering is only about the whole aeroplane, and aerospace encompasses structures, fluid mechanics, etc. which he doesn't think is included in aeronautical engineering.
Well, tell them they're wrong.
Even in the far distant past when I got my degree, structures, supersonic flow, etc. were all part of the curriculum. Even if I went into the "Stability and Control" branch in the end.
Aircraft and spacecraft are two branches of the same tree.