Index: uspace/lib/label/src/mbr.c
===================================================================
--- uspace/lib/label/src/mbr.c	(revision deacc58d86dbbc4e37a7d1534bd9933e671162e1)
+++ uspace/lib/label/src/mbr.c	(revision 5cd1eb9a685b70d040e94a7023215fb9b2466ffd)
@@ -39,4 +39,5 @@
 #include <stdlib.h>
 
+#include "std/fat.h"
 #include "std/mbr.h"
 #include "mbr.h"
@@ -89,4 +90,5 @@
 	label_t *label = NULL;
 	mbr_br_block_t *mbr = NULL;
+	fat_bs_t *bs;
 	mbr_pte_t *eptr;
 	uint16_t sgn;
@@ -124,4 +126,6 @@
 	}
 
+	bs = (fat_bs_t *)mbr;
+
 	rc = bd->ops->read(bd->arg, mbr_ba, 1, mbr);
 	if (rc != EOK) {
@@ -145,4 +149,12 @@
 	}
 
+	/*
+	 * We can't really tell whether this is an MBR. Make sure
+	 * this is not actually the BR of a FAT file system
+	 */
+	if (bs->type[0] == 'F' && bs->type[1] == 'A' && bs->type[2] == 'T') {
+		rc = EIO;
+		goto error;
+	}
 
 	label->ext_part = NULL;