diff --git a/docs/.docker/Dockerfile b/docs/.docker/Dockerfile
index a9900af7..237c75e8 100644
--- a/docs/.docker/Dockerfile
+++ b/docs/.docker/Dockerfile
@@ -46,13 +46,18 @@ ENV PUPPETEER_EXECUTABLE_PATH=/usr/bin/chromium-browser \
 #   - @antora/lunr-extension   : offline full-text search
 #   - asciidoctor-kroki        : escape hatch only; the playbook should
 #                                use the local mermaid extension instead.
+# antora/cli: aa33c8283f9cbc76df93201bec5f8421e8f59a43 -> v3.1.15
+# antora/site-generator: aa33c8283f9cbc76df93201bec5f8421e8f59a43 -> v3.1.15
+# antora/lunr-extension: 41975fc8f62cb2219a2de2f618de1ae1482bd0ce -> v1.0.0-alpha.8
+# mermaid-js/mermaid-cli: a85b11df7064498d5b6b97ee9b2d4a7c10cb42ae -> v11.16.0
+# asciidoctor-kroki: d02fbf06cdb837524f5e4e12537c05e0bb83c715 -> v0.18
 WORKDIR /opt/antora
 RUN npm init -y && npm i --save-exact \
-      @antora/cli@3.1 \
-      @antora/site-generator@3.1 \
-      @antora/lunr-extension@1.0.0-alpha.8 \
-      @mermaid-js/mermaid-cli@11 \
-      asciidoctor-kroki@0.18 \
+      https://gitlab.com/antora/antora/-/tree/aa33c8283f9cbc76df93201bec5f8421e8f59a43/packages/cli \
+      https://gitlab.com/antora/antora/-/tree/aa33c8283f9cbc76df93201bec5f8421e8f59a43/packages/site-generator \
+      https://gitlab.com/antora/antora-lunr-extension/-/commit/41975fc8f62cb2219a2de2f618de1ae1482bd0ce \
+      https://github.com/mermaid-js/mermaid-cli/tree/a85b11df7064498d5b6b97ee9b2d4a7c10cb42ae \
+      https://github.com/asciidoctor/asciidoctor-kroki.git#d02fbf06cdb837524f5e4e12537c05e0bb83c715 \
     && npm cache clean --force
 
 # Make installed modules resolvable even when the workdir is the mounted