diff --git a/filesystem/fat32/testdata/fat32.go b/filesystem/fat32/testdata/fat32.go
index ec404e60..a96c3895 100644
--- a/filesystem/fat32/testdata/fat32.go
+++ b/filesystem/fat32/testdata/fat32.go
@@ -27,6 +27,8 @@ func main() {
 		mkRandFile(fs, "/b/sub"+inc+"/blob/randFileSize", r.Intn(73))
 		mkSmallFile(fs, "/b/sub"+inc+"/blob/testfile3")
 	}
+	mkGigFile(fs, "/b/sub49/blob/testfile4")
+	mkGigFile(fs, "/b/sub50/blob/testfile4")
 	mkSmallFile(fs, "/b/sub55/blob/testfile4")
 	mkGigFile(fs, "/b/sub55/blob/testfile5")
 	entries, err := fs.ReadDir("/b/sub50/blob")
@@ -41,7 +43,7 @@ func main() {
 	fmt.Println("/b/sub55/blob/:\n\n", entries)
 }
 func mkfs(name string) filesystem.FileSystem {
-	size := int64(5 * 1024 * 1024 * 1024)
+	size := int64(6 * 1024 * 1024 * 1024)
 	d, err := diskfs.Create(name, size, diskfs.Raw, diskfs.SectorSizeDefault)
 	if err != nil {
 		fmt.Printf("error creating disk: %v", err)