Index: uspace/srv/fs/fat/fat_fat.c
===================================================================
--- uspace/srv/fs/fat/fat_fat.c	(revision 444a54e8bfec0113991b4f42b33fc28f39fb3e85)
+++ uspace/srv/fs/fat/fat_fat.c	(revision eb73a50a7c9c0264e01ac6afa6c37410632d035f)
@@ -361,5 +361,5 @@
 	uint16_t rscnt;
 	uint16_t sf;
-	uint16_t ts;
+	uint32_t ts;
 	unsigned rde;
 	unsigned rds;
@@ -379,5 +379,7 @@
 	sf = uint16_t_le2host(bs->sec_per_fat);
 	rde = uint16_t_le2host(bs->root_ent_max);
-	ts = uint16_t_le2host(bs->totsec16);
+	ts = (uint32_t) uint16_t_le2host(bs->totsec16);
+	if (ts == 0)
+		ts = uint32_t_le2host(bs->totsec32);
 
 	rds = (sizeof(fat_dentry_t) * rde) / bps;