--- /home/maxx/dfbsd/dfbsd/sys/dev/disk/nata/atapi-fd.c	2026-07-22 16:41:59.436308740 +0000
+++ sys/dev/disk/nata/atapi-fd.c	2026-10-24 09:11:52.098751509 +0000
@@ -406,8 +406,8 @@
 	    fdp->heads = capabilities.heads;
 	    fdp->sectors = capabilities.sectors;
 	    fdp->sectorsize = be16toh(capabilities.sector_size);
-	    fdp->mediasize = be16toh(capabilities.cylinders) *
-			     fdp->heads * fdp->sectors * fdp->sectorsize;
+	    fdp->mediasize = (u_int64_t)be16toh(capabilities.cylinders) *
+		     (u_int64_t)fdp->heads * fdp->sectors * fdp->sectorsize;
 	    if (!capabilities.medium_type)
 		fdp->mediasize = 0;
 	    return 0;