diff --git a/package.json b/package.json
index cd4697b0..c6efc49d 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "test:js": "mocha test/**_test.js",
     "lint": "standard lib/**.js test/**.js tasks/**js",
     "publish": "node tasks/publish.js",
-    "test:update-linux-reference": "docker build -f test/Dockerfile -t asciidoctor-web-pdf/test . && docker run --name asciidoctorwebpdftest asciidoctor-web-pdf/test:latest && docker cp asciidoctorwebpdftest:/app/test/output ./test/reference/linux/"
+    "test:update-linux-reference": "docker build -f test/Dockerfile -t asciidoctor-web-pdf/test . && docker run --name asciidoctorwebpdftest asciidoctor-web-pdf/test:latest; docker cp asciidoctorwebpdftest:/app/test/output/. ./test/reference/linux/ && docker rm asciidoctorwebpdftest"
   },
   "repository": {
     "type": "git",
diff --git a/test/Dockerfile b/test/Dockerfile
index 22755998..671e798d 100644
--- a/test/Dockerfile
+++ b/test/Dockerfile
@@ -9,14 +9,14 @@ RUN apt-get update \
 USER asciidoc
 WORKDIR /app
 
+COPY --chown=asciidoc:asciidoc package.json package-lock.json ./
+RUN npm ci && npm cache clean --force
+
 COPY --chown=asciidoc:asciidoc lib ./lib
 COPY --chown=asciidoc:asciidoc bin ./bin
 COPY --chown=asciidoc:asciidoc css ./css
 COPY --chown=asciidoc:asciidoc fonts ./fonts
 COPY --chown=asciidoc:asciidoc test ./test
 
-COPY --chown=asciidoc:asciidoc package.json package-lock.json ./
-RUN npm ci
-
 ENV DEBUG=1
 CMD npm t