diff --git a/.github/workflows/docker-build.yml b/.github/workflows/docker-build.yml
index 0d26fd22..9f2de2d0 100644
--- a/.github/workflows/docker-build.yml
+++ b/.github/workflows/docker-build.yml
@@ -27,7 +27,7 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           build-args: |
-            CI="true"
+            CI=true
           file: './${{ matrix.image }}'
           secrets: github_token=${{ secrets.GITHUB_TOKEN }}
           push: false
diff --git a/Dockerfile.PersonsApi b/Dockerfile.PersonsApi
index 21e5e79a..62beebb3 100644
--- a/Dockerfile.PersonsApi
+++ b/Dockerfile.PersonsApi
@@ -3,6 +3,9 @@ WORKDIR /build
 
 ENV DEBIAN_FRONTEND=noninteractive
 
+ARG CI
+ENV CI=${CI}
+
 COPY . .
 
 RUN --mount=type=secret,id=github_token dotnet nuget add source --username USERNAME --password $(cat /run/secrets/github_token) --store-password-in-clear-text --name github "https://nuget.pkg.github.com/DFE-Digital/index.json"