diff --git a/src/FeedIo/Standard/Rss.php b/src/FeedIo/Standard/Rss.php
index bb2dd7dc..5e3e9cc9 100644
--- a/src/FeedIo/Standard/Rss.php
+++ b/src/FeedIo/Standard/Rss.php
@@ -94,7 +94,7 @@ public function buildFeedRuleSet() : RuleSet
     {
         $ruleSet = $this->buildBaseRuleSet();
         $ruleSet->add(new Language())
-            ->add($this->getModifiedSinceRule(static::DATE_NODE_TAGNAME));
+            ->add($this->getModifiedSinceRule(static::DATE_NODE_TAGNAME), ['lastBuildDate', 'lastPubDate']);
 
         return $ruleSet;
     }