diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a77191d6..108bd23f 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -172,7 +172,7 @@ jobs:
   htmlcheck:
     name: "🔎 Validate generated HTML"
     runs-on: ubuntu-latest
-    needs: [build-spec]
+    needs: [calculate-baseurl, build-spec]
     steps:
       - name: "📥 Source checkout"
         uses: actions/checkout@v2
@@ -183,8 +183,14 @@ jobs:
           name: spec-artifact
 
       - name: "📝 Unpack the spec"
+        # we have to unpack it into the right path given the baseurl, so that the
+        # links are correct.
+        # eg if baseurl is `/unstable`, we want to put the site in `spec/unstable`.
         run: |
-          tar -xvzf spec.tar.gz
+          mkdir -p "spec${baseURL}"
+          tar -C "spec${baseURL}" --strip-components=1 -xvzf spec.tar.gz
+        env:
+          baseURL: "${{ needs.calculate-baseurl.outputs.baseURL }}"
 
       - name: "Run htmltest"
         uses: wjdp/htmltest-action@master
diff --git a/changelogs/internal/newsfragments/1338.clarification b/changelogs/internal/newsfragments/1338.clarification
new file mode 100644
index 00000000..c5b60e24
--- /dev/null
+++ b/changelogs/internal/newsfragments/1338.clarification
@@ -0,0 +1 @@
+Use a link checker to ensure that we do not have broken links.