diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f300026..83bdc4e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,3 +25,21 @@ jobs:
           for f in docs/migrate/*.sh; do
             cmp "$f" "site/migrate/$(basename "$f")"
           done
+      # Anchors come from heading text, so an edited heading breaks every link
+      # pointing at it, including links on pages nobody touched.
+      #
+      # mkdocs has validation.links.anchors and it is not enabled here, which
+      # looks like the cheaper option until you check what it covers. It reads
+      # source markdown; this reads built HTML. Measured on this site: a raw
+      # <a href> and a root-absolute link, both pointing at headings that do
+      # not exist, pass mkdocs and fail here.
+      #
+      # print_page/ is the single-page export from mkdocs-print-site-plugin. It
+      # rewrites every fragment into ids of its own, so its anchors are not the
+      # site's. All 690 links the exclusion drops are page-local fragments of
+      # that generated page; no authored link is silenced.
+      #
+      # Last, because it is the step most likely to go red and a job stops at
+      # its first failure.
+      - name: Check anchors
+        run: uv run check-anchors site --exclude 'print_page/*'
diff --git a/pyproject.toml b/pyproject.toml
index a065557..cfa5af2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,4 +8,5 @@ dependencies = [
     "mkdocs-with-pdf>=0.9",
     "click<8.3",
     "mkdocs-print-site-plugin>=2.8",
+    "halos-docs-tools @ git+https://github.com/halos-org/docs-tools@v0.1.0",
 ]
diff --git a/uv.lock b/uv.lock
index dcdbed7..73b086c 100644
--- a/uv.lock
+++ b/uv.lock
@@ -375,6 +375,7 @@ version = "0.1.0"
 source = { virtual = "." }
 dependencies = [
     { name = "click" },
+    { name = "halos-docs-tools" },
     { name = "mkdocs-material" },
     { name = "mkdocs-print-site-plugin" },
     { name = "mkdocs-with-pdf" },
@@ -383,11 +384,20 @@ dependencies = [
 [package.metadata]
 requires-dist = [
     { name = "click", specifier = "<8.3" },
+    { name = "halos-docs-tools", git = "https://github.com/halos-org/docs-tools?rev=v0.1.0" },
     { name = "mkdocs-material", specifier = ">=9.5" },
     { name = "mkdocs-print-site-plugin", specifier = ">=2.8" },
     { name = "mkdocs-with-pdf", specifier = ">=0.9" },
 ]
 
+[[package]]
+name = "halos-docs-tools"
+version = "0.1.0"
+source = { git = "https://github.com/halos-org/docs-tools?rev=v0.1.0#7f09d05f54cf64184a7a4d7205c166bc49ec0f6e" }
+dependencies = [
+    { name = "pyyaml" },
+]
+
 [[package]]
 name = "idna"
 version = "3.11"