Valgrind's definite memory leaks are not displayed

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
    int * foo = malloc (100);
    return 0;
}

100 bytes in 1 blocks are definitely lost in loss record 1 of 1
  in main in /home/marcin/proj/foobar/main.c:6
  1: malloc in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so
  2: main in /home/marcin/proj/foobar/main.c:6