diff --git a/.github/workflows/auto-update.yml b/.github/workflows/auto-update.yml
index 99c01b5..408276e 100644
--- a/.github/workflows/auto-update.yml
+++ b/.github/workflows/auto-update.yml
@@ -72,7 +72,9 @@ jobs:
             exit 0
           else
             echo "Building nautobot-lab:$NAUTOBOT_VERSION"
-            docker build -t networktocode/nautobot-lab:${NAUTOBOT_VERSION} .
+            docker build \
+              --build-arg NAUTOBOT_VERSION=${NAUTOBOT_VERSION} \
+              -t networktocode/nautobot-lab:${NAUTOBOT_VERSION} .
             echo "Building nautobot-lab:latest with $NAUTOBOT_VERSION"
             docker build -t networktocode/nautobot-lab:latest .
             echo "Logging into Docker Hub"
diff --git a/Dockerfile b/Dockerfile
index dc42563..fa38d45 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,8 @@
 FROM public.ecr.aws/ubuntu/ubuntu:22.04_stable
 
-ENV NAUTOBOT_VERSION="1.5.20"
+ARG NAUTOBOT_VERSION="1.5.21"
+
+ENV NAUTOBOT_VERSION=${NAUTOBOT_VERSION}
 
 ENV NAUTOBOT_ROOT="/opt/nautobot"