diff --git a/files.c b/files.c
index b1cff54ba..ad3c2d6e3 100644
--- a/files.c
+++ b/files.c
@@ -118,7 +118,7 @@ static int collect_fd(int pid, struct fdinfo_entry *e)
 
 	for (i = 0; i < nr_fdinfo_descs; i++) {
 		desc = &fdinfo_descs[i];
-		if (strncmp(desc->id, e->id, FD_ID_SIZE))
+		if (strncmp(desc->id, (char *) e->id, FD_ID_SIZE))
 			continue;
 
 		fdinfo_descs[i].users++;
@@ -465,7 +465,7 @@ static int open_fdinfo(int pid, struct fdinfo_entry *fe, int *fdinfo_fd, int sta
 	u32 mag;
 	int ret;
 
-	struct fdinfo_desc *fi = find_fd(fe->id);
+	struct fdinfo_desc *fi = find_fd((char *)fe->id);
 
 	if (move_img_fd(fdinfo_fd, (int)fe->addr))
 		return -1;
diff --git a/include/image.h b/include/image.h
index 571796849..e16586175 100644
--- a/include/image.h
+++ b/include/image.h
@@ -29,7 +29,7 @@ struct fdinfo_entry {
 	u16	flags;
 	u32	pos;
 	u64	addr;
-	char	id[FD_ID_SIZE];
+	u8	id[FD_ID_SIZE];
 	u8	name[0];
 } __packed;