diff --git a/autoinstall/build-iso.sh b/autoinstall/build-iso.sh
index 0bc6e5a..4a30078 100644
--- a/autoinstall/build-iso.sh
+++ b/autoinstall/build-iso.sh
@@ -66,6 +66,20 @@ rsync -a --delete \
   "$PACKAGE_DIR/" "$WORK_DIR/cezen-aipackage/"
 echo "✓ Installer payload bundled"
 
+# ── Refresh installer checksum manifest ─────────────────
+echo "→ Refreshing md5sum.txt..."
+(
+  cd "$WORK_DIR"
+  rm -f md5sum.txt
+  find . -type f \
+    ! -path './md5sum.txt' \
+    ! -path './boot.catalog' \
+    -print0 \
+    | sort -z \
+    | xargs -0 md5sum > md5sum.txt
+)
+echo "✓ md5sum.txt refreshed"
+
 # ── Patch GRUB ────────────────────────────────
 echo "→ Patching GRUB config..."
 GRUB_CFG="$WORK_DIR/boot/grub/grub.cfg"