diff --git a/sim/src/main.rs b/sim/src/main.rs
index 2c53d22..f077668 100644
--- a/sim/src/main.rs
+++ b/sim/src/main.rs
@@ -264,10 +264,10 @@
         img_size: len as u32,
         flags: 0,
         ver: ImageVersion {
-            major: 1,
+            major: (offset / (128 * 1024)) as u8,
             minor: 0,
             revision: 1,
-            build_num: 1,
+            build_num: offset as u32,
         },
         _pad3: 0,
     };