diff --git a/disk/disk_openbsd.go b/disk/disk_openbsd.go
index 2b0ce10..b191222 100644
--- a/disk/disk_openbsd.go
+++ b/disk/disk_openbsd.go
@@ -134,7 +134,7 @@ func UsageWithContext(_ context.Context, path string) (*UsageStat, error) {
 		Path:        path,
 		Fstype:      getFsType(stat),
 		Total:       (uint64(stat.F_blocks) * uint64(bsize)),
-		Free:        (uint64(stat.F_bavail) * uint64(bsize)),
+		Free:        (uint64(stat.F_bfree) * uint64(bsize)),
 		InodesTotal: (uint64(stat.F_files)),
 		InodesFree:  (uint64(stat.F_ffree)),
 	}
diff --git a/disk/disk_unix.go b/disk/disk_unix.go
index 482372d..0c637f2 100644
--- a/disk/disk_unix.go
+++ b/disk/disk_unix.go
@@ -22,7 +22,7 @@ func UsageWithContext(_ context.Context, path string) (*UsageStat, error) {
 		Path:        unescapeFstab(path),
 		Fstype:      getFsType(stat),
 		Total:       (uint64(stat.Blocks) * uint64(bsize)),
-		Free:        (uint64(stat.Bavail) * uint64(bsize)),
+		Free:        (uint64(stat.Bfree) * uint64(bsize)),
 		InodesTotal: (uint64(stat.Files)),
 		InodesFree:  (uint64(stat.Ffree)),
 	}