diff --git a/.gitignore b/.gitignore
index 184eff81..8f0288da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,5 @@ Package.resolved
 **/*.docc/header.html
 **/*.docc/footer.html
 scripts/__pycache__/
+.coverage
+.coverage.*
diff --git a/scripts/build_docs.py b/scripts/build_docs.py
index b5f9672b..477118e7 100755
--- a/scripts/build_docs.py
+++ b/scripts/build_docs.py
@@ -55,6 +55,7 @@ class ArchiveFetchError(Exception):
     "--experimental-enable-custom-templates",
     "--enable-mentioned-in",
     # "--enable-experimental-external-link-support",
+    "--enable-experimental-code-block-annotations",
     # Emit a markdown copy of every rendered document (plus a manifest) under
     # data/documentation/. These sidecar files survive docc merge and
     # process-archive transform-for-static-hosting, so they reach the published