I am trying out the offsetof macro. Is my usage of it with the casts well-defined and correct?

#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>

enum foo { X, Y, Z };

struct foo_struct {
        int32_t x;
        int32_t y;
        int32_t z;
};

static int offset(enum foo f)
{
        switch (f) {
        case X:
                return offsetof(struct foo_struct, x);
        case Y:
                return offsetof(struct foo_struct, y);
        case Z:
                return offsetof(struct foo_struct, z);
        }
}

static int32_t get(struct foo_struct *fs, enum foo f)
{
        return *(int32_t *)((char *)fs + offset(f));
}

static void set(struct foo_struct *fs, enum foo f, int32_t v)
{
        *(int32_t *)((char *)fs + offset(f)) = v;
}

int main(void)
{
        struct foo_struct fs;

        set(&fs, X, 24601);
        set(&fs, Y, 3141);
        set(&fs, Z, 42);

        assert(get(&fs, X) == 24601);
        assert(get(&fs, Y) == 3141);
        assert(get(&fs, Z) == 42);
}

The following question only applies if my usage is correct and not UB. Compiling with clang and -Weverything, I get the following warnings:

warning: cast from 'char *' to 'int32_t *' (aka 'int *') increases required alignment from 1 to 4 [-Wcast-align]
        return *(int32_t *)((char *)fs + offset(f));
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
warning: cast from 'char *' to 'int32_t *' (aka 'int *') increases required alignment from 1 to 4 [-Wcast-align]
        *(int32_t *)((char *)fs + offset(f)) = v;
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Is there any way to disable these in code (i.e. without doing -Wno-cast-align), as my understanding is that in this case they aren’t relevant as we know from the struct layout that the cast is ok.