diff --git a/NumLib/DOF/LocalToGlobalIndexMap.h b/NumLib/DOF/LocalToGlobalIndexMap.h
index 7794a39e845d1a024d20a4636d354371f004af52..2ec3b7abf04f43f777552a6a68be455a77cb810f 100644
--- a/NumLib/DOF/LocalToGlobalIndexMap.h
+++ b/NumLib/DOF/LocalToGlobalIndexMap.h
@@ -44,7 +44,7 @@ class LocalToGlobalIndexMap final
 {
     // Enables using std::make_unique with private constructors from within
     // member functions of LocalToGlobalIndexMap. Cf.
-    // https://seanmiddleditch.com/enabling-make-unique-with-private-constructors/
+    // https://web.archive.org/web/20210302195245/https://seanmiddleditch.com/enabling-make-unique-with-private-constructors/
     struct ConstructorTag
     {
         explicit ConstructorTag() = default;
diff --git a/scripts/ci/jobs/build-docs.yml b/scripts/ci/jobs/build-docs.yml
index c622f27b3651b540be78e71e3fb5f329a75d28e1..a15f02e9606a1c664d6764d29e9a76af3a1a20f9 100644
--- a/scripts/ci/jobs/build-docs.yml
+++ b/scripts/ci/jobs/build-docs.yml
@@ -14,6 +14,8 @@ build docs:
   retry:
     max: 2
     when: runner_system_failure
+  variables:
+    DOX_WARNINGS_THRESHOLD: 16
   before_script:
     # HACK to easier linking to the generated pages
     - echo '<meta http-equiv="REFRESH" content="0;URL=build/docs/index.html">' >> Doxygen.html
@@ -23,7 +25,13 @@ build docs:
     - cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release -DOGS_USE_CONAN=OFF -DOGS_USE_POETRY=OFF -DOGS_BUILD_PROCESSES=SteadyStateDiffusion
     - cmake --build . --target doc > >(tee make-docs.output)
     - cat DoxygenWarnings.log|grep -v 'too many nodes'
-    - echo "doxygen_warnings `cat DoxygenWarnings.log|grep warning:|grep -v 'too many nodes'|wc -l|xargs`" > metrics.txt
+    - NUM_DOX_WARNINGS=`cat DoxygenWarnings.log|grep warning:|grep -v 'too many nodes'|wc -l|xargs`
+    - echo "doxygen_warnings $NUM_DOX_WARNINGS" > metrics.txt
+    - |
+      if [[ ( "$NUM_DOX_WARNINGS" > "$DOX_WARNINGS_THRESHOLD" ) ]]; then
+        echo "Error: Number of Doxygen warnings exceeded threshold –> $NUM_DOX_WARNINGS > $DOX_WARNINGS_THRESHOLD"
+        exit 1
+      fi
     - |
       if [ "$DEPLOY" == "true" ]; then
         if [ "$ON_MASTER" == "true" ]; then