diff --git a/Dockerfile b/Dockerfile
index 4fce584..0e52271 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,8 @@
 # Stage: base image
-FROM node:14.17-buster-slim as base
+ARG BUILD_NUMBER
+ARG GIT_REF
 
-ARG BUILD_NUMBER=1_0_0
-ARG GIT_REF=not-available
+FROM node:14.17-buster-slim as base
 
 LABEL maintainer="HMPPS Digital Studio <info@digital.justice.gov.uk>"
 
@@ -19,6 +19,8 @@ RUN apt-get update && \
 
 # Stage: build assets
 FROM base as build
+ARG BUILD_NUMBER
+ARG GIT_REF
 
 RUN apt-get install -y make python g++
 
@@ -28,6 +30,8 @@ RUN CYPRESS_INSTALL_BINARY=0 npm ci --no-audit
 COPY . .
 RUN npm run build
 
+ENV BUILD_NUMBER ${BUILD_NUMBER:-1_0_0}
+ENV GIT_REF ${GIT_REF:-dummy}
 RUN export BUILD_NUMBER=${BUILD_NUMBER} && \
     export GIT_REF=${GIT_REF} && \
     npm run record-build-info