diff --git a/Rakefile b/Rakefile
index 5b84c5a..9490819 100644
--- a/Rakefile
+++ b/Rakefile
@@ -6,5 +6,6 @@ task :test do
   HTMLProofer.check_directory('./_site',
                               check_html: true,
                               validation: { ignore_script_embeds: true },
+                              empty_alt_ignore: true,
                               url_swap: { %r{http://opendefinition.org} => '' }).run
 end