Problem compiling DOOM source: error: initializer element is not constant (integer conversion)

I'm trying to get the original Doom code compiling. I already fixed some errors but I don't know what this means. I'm not that good at C...

Example error (there are more errors, but they're the same):

m_misc.c:249:40: note: (near initialization for ‘defaults[16].defaultvalue’)
m_misc.c:250:42: error: initializer element is not constant
  250 |         {"mousetype", (int *)&mousetype, (int)"microsoft"},
      |                                          ^

As you can see it's marking the integer conversion.

This is the relevant part of the code. It's actually more, but it's repeating itself (more chat macro defining, etc.) so I shortened it a bit

typedef struct
{
    char *name;
    int *location;
    int defaultvalue;
    int scantranslate; // PC scan code hack
    int untranslated;  // lousy hack
} default_t;

default_t defaults[] =
{
    {"mousedev", (int *)&mousedev, (int)"/dev/ttyS0"},
    {"mousetype", (int *)&mousetype, (int)"microsoft"},
    {"chatmacro0", (int *)&chat_macros[0], (int)HUSTR_CHATMACRO0},
    {"chatmacro1", (int *)&chat_macros[1], (int)HUSTR_CHATMACRO1},
};
     

I'm using gcc 10.1.0-2 under Linux.

Thanks in advance for any help:)