Index: uspace/app/mkmfs/mkmfs.c
===================================================================
--- uspace/app/mkmfs/mkmfs.c	(revision c8bb1633179eac7fd20f31e4d8188f34bf5747ef)
+++ uspace/app/mkmfs/mkmfs.c	(revision 8f2eca0d71e34991f3100a8ad7cd69d5a57ab184)
@@ -649,5 +649,5 @@
 		mark_bmap(ibmap_buf, i, FREE);
 
-	for (i = sb->first_data_zone + 1; i < sb->n_zones; ++i)
+	for (i = 2; i < sb->n_zones; ++i)
 		mark_bmap(zbmap_buf, i, FREE);