Fortran: Source files do not always need to be preprocessed

I tried to use cmake+ninja(fortran) to build my project which contains about 1500 source files with no modules expecting to be faster than cmake+make. After launching the build it takes 2x build time of cmake+make and all of this is because of unnecessary preprocessing of fortran files. Is there a way or a workaround to disable the preprocessing. Is it necessary to preprocess fortran files to build dependencies?! Isn't sufficient to use (cmake+make) way to build dependencies!