how to prevent cubase not to convert mp3 to wav?

i use sometimes tracks that i have to reference in my project.

so i add them into the project and it’s usually mp3 files. but even if i de-tick the box of copy file to project folder, cubase somehow always convert that mp3 to wav, so by that it’s copied to the project file and instead of 10mb it’s becoming 50mb.

is there a way that i can use mp3 files in my project and cubase NOT to convert them to wav files and copy it to project folder so i can save space?


If you have C6 V6.5 or higher you could use FLAC files, but why worry? Space is cheap.