Index: util.c
--- util.c.orig
+++ util.c
@@ -192,6 +192,7 @@ void *mem_chunk(off_t base, size_t len, const char *de
 	 || (geteuid() == 0 && !S_ISCHR(statbuf.st_mode)))
 	{
 		fprintf(stderr, "Can't read memory from %s\n", devmem);
+		fprintf(stderr, "Do you need to set kern.allowkmem=1 in sysctl.conf and reboot?\n");
 		if (fd == -1)
 			return NULL;
 		goto out;