diff --git a/README.md b/README.md
index b14c83ae..709d97db 100644
--- a/README.md
+++ b/README.md
@@ -59,15 +59,12 @@ It checks a broad set of points: internal and external links existence (alerting
 
 To install it, It has been incorporated in the Gemfile so the previous dependency install command would have already installed it.
 
-You can run the following gem to tests the generated site.
-
-```bash
-bundle exec jekyll build
-bundle exec htmlproofer ./_site
-```
-
-A utility script has also been included to run these checks in a CI system smoothly.
+You can run `bundle exec jekyll build` followed by `bundle exec htmlproofer ./_site` to build and test the generated site.
+However, note that a comprehensive configuration is required for the htmlproofer.
+Therefore, we strongly suggest to run the utility script at
 
 ```bash
 ./scripts/cibuild
 ```
+
+which is also used for CI.
diff --git a/scripts/cibuild b/scripts/cibuild
index 497056d0..1a10abee 100755
--- a/scripts/cibuild
+++ b/scripts/cibuild
@@ -29,4 +29,4 @@ IGNORE_HREFS=${IGNORE_HREFS:+$IGNORE_HREFS,}$(ruby -e "puts %w{
 
 echo "Ignoring urls: " $IGNORE_HREFS
 bundle exec jekyll build
-bundle exec htmlproofer --check_html --http-status-ignore "429" --check-favicon --assume-extension --empty-alt-ignore --only-4xx --url-ignore $IGNORE_HREFS $@ ./_site
+bundle exec htmlproofer --check_html --http-status-ignore "429" --check-favicon --assume-extension --alt-ignore "/.*/" --empty-alt-ignore --only-4xx --url-ignore $IGNORE_HREFS $@ ./_site