Typedef redefinition from header files being pulled in from both SDL & SDL2

I’m porting code what was written on Windows in Visual Studio to Linux in C::B. When building, the compiler is complaining about redefinitions of types from headers in /usr/include/SDL2 that are also defined in /usr/include/SDL. Because I’m using sdl2-config --cflag, I’m only supposed to be pulling in headers for SDL2. Does anyone have any clue of what would be causing the older SDL headers to be pulled in with the modern headers? My development environment is:

Ubuntu 20.04.1 LTS
Code::Blocks 20.03

Any help would be greatly appreciated.