Yes you force a path to be a system include by using the optional SYSTEM flag
include_directories(SYSTEM path)
https://cmake.org/cmake/help/latest/command/include_directories.html
Starting with CMake 2.8.12 you can use the new target_include_directories to include system directory includes at the target level, while leveraging the new usage requirement features of cmake:
target_include_directories(foo SYSTEM PUBLIC path)
Now target foo will use path as a system include, and anything that links to foo will also use path as automatically as a system include. You can control the propagation of these usage requirements by changing the PUBLIC keyword to PRIVATE or INTERFACE.
https://cmake.org/cmake/help/latest/command/target_include_directories.html