Initializing argument 4 of void qsort() in C using structures

I have a little problem there with error by using function qsort, it shows me:

[Note] initializing argument 4 of 'void qsort(void*, size_t, size_t, int (*)(const void*, const void*))'

it also shows the error:

[Error] invalid conversion from 'int (*)(const student*, const student*)' to 'int (*)(const void*, const void*)' [-fpermissive]

int n;
            qsort ((void*) databaza, size, sizeof(struct student), compare);
            for (n=0; n<size; n++)
            {  
            printf ("%d %s",databaza[SIZE].votes,databaza[SIZE].name);  
            }
            return 0;

where the compare function looks like

int compare(const struct student* p1, const struct student* p2){
           return ( p1->votes - p2->votes );
}

in structure

struct student {
    char name[SIZE];
    int votes;
};


int find_student(struct student* students,int size, const char* name){
   for(int i = 0;i < size;i++){
    int results=strcmp(students[i].name,name);
      if(results==0){
          return i;
      }
   }
   return -1;
}

Can anyone tell me why is this happening, I am quite new in structures and functions like qsort.