diff --git a/.github/workflows/build_iso.yml b/.github/workflows/build_iso.yml
index 5ec3b37..d3bb8f1 100644
--- a/.github/workflows/build_iso.yml
+++ b/.github/workflows/build_iso.yml
@@ -9,7 +9,7 @@ on:
 
 env:
   IMAGE_REGISTRY: ghcr.io/${{ github.repository_owner }}
-  INSTALLER_VERSION: 40
+  INSTALLER_VERSION: 39
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref || github.run_id }}