diff --git a/CHANGES.rst b/CHANGES.rst
index 2aa057c2..efbbec68 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -14,7 +14,9 @@ New features:
 
 Bug fixes:
 
-- *add item here*
+- Do not use ``rel="tag"`` attribute on the keywords viewlet as the referenced document is not a tag definition but a search result;
+  use ``rel="nofollow"`` instead to avoid search crawlers hammering our sites backend.
+  [hvelarde]
 
 
 2.3.17 (2017-01-17)
diff --git a/plone/app/layout/viewlets/keywords.pt b/plone/app/layout/viewlets/keywords.pt
index afee9132..75dc9592 100644
--- a/plone/app/layout/viewlets/keywords.pt
+++ b/plone/app/layout/viewlets/keywords.pt
@@ -8,7 +8,7 @@
   <span tal:repeat="category categories">
     <a href=""
        class="link-category"
-       rel="tag"
+       rel="nofollow"
        tal:content="category"
        tal:define="quotedCat python:url_quote(category)"
        tal:attributes="href string:${context/@@plone_portal_state/navigation_root_url}/@@search?Subject%3Alist=${quotedCat}">