Index: uspace/srv/fs/fat/fat_ops.c
===================================================================
--- uspace/srv/fs/fat/fat_ops.c	(revision 8b58fc1dc88ef68baf00ced4b0bc133a720ae181)
+++ uspace/srv/fs/fat/fat_ops.c	(revision 00a9625f936cdfac84ac5fd0d5b2f0528fbd99d2)
@@ -343,5 +343,5 @@
 			/* mark all dentries as never-used */
 			memset(b->data, 0, bps);
-			b->dirty = false;
+			b->dirty = true;
 			block_put(b);
 		}