diff --git a/src/machine.rs b/src/machine.rs
index 0d0aa86..1482cd5 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -16,7 +16,7 @@ use netstack::NetStack;
 use heap::Heap;
 
 const MAGIC_HEADER:u32 = 0x1DEA_DFAD;
-const ANTI_BS_SIZE:usize = 0xFFFF;
+const ANTI_BS_SIZE:usize = 0xFF;
 
 pub struct Machine {
     pub wide: bool,