diff --git a/scripts/plugin-npm-publish.sh b/scripts/plugin-npm-publish.sh
index aaf051d4bde..e1c98a68ef2 100644
--- a/scripts/plugin-npm-publish.sh
+++ b/scripts/plugin-npm-publish.sh
@@ -166,8 +166,13 @@ fi
     for dist_tag in "${mirror_dist_tags[@]}"; do
       [[ -n "${dist_tag}" ]] || continue
       echo "Mirroring ${package_name}@${package_version} onto dist-tag ${dist_tag}"
-      NPM_CONFIG_USERCONFIG="${mirror_userconfig}" \
-        npm dist-tag add "${package_name}@${package_version}" "${dist_tag}"
+      if ! NPM_CONFIG_USERCONFIG="${mirror_userconfig}" \
+        npm dist-tag add "${package_name}@${package_version}" "${dist_tag}"; then
+        if [[ "${mirror_auth_requirement}" == "required" ]]; then
+          exit 1
+        fi
+        echo "Warning: optional npm dist-tag mirror failed for ${package_name}@${package_version} -> ${dist_tag}; published package remains live." >&2
+      fi
     done
   fi
 )