Index: uspace/app/mkexfat/mkexfat.c
===================================================================
--- uspace/app/mkexfat/mkexfat.c	(revision 8efc4c1f20a1467521ebc2a5707702b311fb90dc)
+++ uspace/app/mkexfat/mkexfat.c	(revision b4b3cb051e9b5987ef1e8f268a724f9d1a683f19)
@@ -133,5 +133,5 @@
 	printf("Usage: mkexfat [options] <device>\n"
 	    "-c, --cluster-size ## Specify the cluster size (Kb)\n"
-	    "-s, --fs-size ##      Specify the filesystem size (byte)\n");
+	    "-s, --fs-size ##      Specify the filesystem size (sectors)\n");
 }
 
@@ -761,9 +761,4 @@
 		case 's':
 			user_fs_size = (aoff64_t) strtol(optarg, NULL, 10);
-			if (user_fs_size < 1024 * 1024) {
-				printf(NAME ": Error, fs size can't be less"
-				    " than 1 Mb.\n");
-				return 1;
-			}
 			break;
 
@@ -812,4 +807,12 @@
 	}
 
+	user_fs_size *= cfg.sector_size;
+	if (user_fs_size < 1024 * 1024) {
+		printf(NAME ": Error, fs size can't be less"
+		    " than 1 Mb.\n");
+		return 1;
+	}
+
+
 	if (cfg.sector_size > 4096) {
 		printf(NAME ": Error, sector size can't be greater" \