Why is name mangling used with the WinMain() function?

Based on my understanding, name mangling is used when there is function overloading, so that the functions with the same name can be distinguished.

But I have noticed that name mangling is also used with the WinMain() function (which is not overloaded). After name mangling it becomes _WinMain@16.

So why is name mangling used with the WinMain() function?

This is the code that I used:

#include <windows.h>

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
    LPSTR lpCmdLine, int nCmdShow)
{

    return 0;
}