diff --git a/bios/stage-2/src/fat.rs b/bios/stage-2/src/fat.rs
index 9ce41d6f..0f24e0b4 100644
--- a/bios/stage-2/src/fat.rs
+++ b/bios/stage-2/src/fat.rs
@@ -48,16 +48,14 @@ impl Bpb {
         let root_cluster;
         let fat_size_32;
 
-        if (total_sectors_16 == 0) && (total_sectors_32 != 0) {
+        if fat_size_16 == 0 {
             // FAT32
             fat_size_32 = u32::from_le_bytes(raw[36..40].try_into().unwrap());
             root_cluster = u32::from_le_bytes(raw[44..48].try_into().unwrap());
-        } else if (total_sectors_16 != 0) && (total_sectors_32 == 0) {
+        } else {
             // FAT12 or FAT16
             fat_size_32 = 0;
             root_cluster = 0;
-        } else {
-            panic!("ExactlyOneTotalSectorsFieldMustBeZero");
         }
 
         Self {
diff --git a/tests/ramdisk.rs b/tests/ramdisk.rs
index 08c86f9b..6c23615a 100644
--- a/tests/ramdisk.rs
+++ b/tests/ramdisk.rs
@@ -1,6 +1,8 @@
 use std::path::Path;
 
 use bootloader_test_runner::run_test_kernel_with_ramdisk;
+use tempfile::NamedTempFile;
+
 static RAMDISK_PATH: &str = "tests/ramdisk.txt";
 
 #[test]
@@ -26,3 +28,15 @@ fn memory_map() {
         Some(Path::new(RAMDISK_PATH)),
     );
 }
+
+#[test]
+fn large_ramdisk() {
+    // Create a large file to act as the RAM disk.
+    let ramdisk = NamedTempFile::new().unwrap();
+    ramdisk.as_file().set_len(1024 * 1024 * 16).unwrap();
+
+    run_test_kernel_with_ramdisk(
+        env!("CARGO_BIN_FILE_TEST_KERNEL_RAMDISK_basic_boot"),
+        Some(ramdisk.as_ref()),
+    );
+}