diff --git a/Containerfile b/Containerfile
index 047367e..51474b3 100644
--- a/Containerfile
+++ b/Containerfile
@@ -4,6 +4,8 @@
 # Build args can be provided on the commandline when building locally with:
 #   podman build -f Containerfile --build-arg FEDORA_MAJOR_VERSION=40 -t local-image
 
+ARG FEDORA_MAJOR_VERSION="${FEDORA_MAJOR_VERSION:-40}"
+
 # SOURCE_IMAGE arg can be anything from ublue upstream which matches your desired version:
 # See list here: https://github.com/orgs/ublue-os/packages?repo_name=main
 # - "silverblue"
@@ -36,9 +38,8 @@ ARG SOURCE_IMAGE="base"
 ARG SOURCE_SUFFIX="-nvidia"
 
 ## SOURCE_TAG arg must be a version built for the specific image: eg, 39, 40, gts, latest
-ARG SOURCE_TAG="latest"
+ARG SOURCE_TAG="${FEDORA_MAJOR_VERSION}"
 
-ARG FEDORA_MAJOR_VERSION="${FEDORA_MAJOR_VERSION:-40}"
 
 ### 2. SOURCE IMAGE
 ## this is a standard Containerfile FROM using the build ARGs above to select the right upstream image