diff --git a/templates/test/by_id.html b/templates/test/by_id.html
index d3964cb6..2dc57206 100644
--- a/templates/test/by_id.html
+++ b/templates/test/by_id.html
@@ -287,7 +287,7 @@ <h6>There are no tests executed in this category.</h6>
                     reveal.innerHTML = resp;
                     reveal.innerHTML +=
                         '<a href="'+diff_download_url+'" target="_blank">' +
-                            '<button type="button">' +
+                            '<button type="button" class="button">' +
                             'Download Full Diff' +
                             '</button>' +
                         '</a>, only first 50 shown here.';