diff --git a/ext/rss_images/main.php b/ext/rss_images/main.php
index 5f26b54c..f72b54d3 100644
--- a/ext/rss_images/main.php
+++ b/ext/rss_images/main.php
@@ -115,7 +115,7 @@ class RSSImages extends Extension
 		</item>
 		";
 
-        $cache->set("rss-item-image:{$image->id}", $data, 86400);
+        $cache->set("rss-item-image:{$image->id}", $data, rand(43200, 86400));
 
         return $data;
     }
diff --git a/themes/rule34v2/themelet.class.php b/themes/rule34v2/themelet.class.php
index cd4f0a18..6f2b7aeb 100644
--- a/themes/rule34v2/themelet.class.php
+++ b/themes/rule34v2/themelet.class.php
@@ -32,7 +32,7 @@ class Themelet extends BaseThemelet
                "</div>\n";
 
         // cache for ages; will be cleared in ext/index:onImageInfoSet
-        $cache->set("thumb-block:{$image->id}", $html, 86400);
+        $cache->set("thumb-block:{$image->id}", $html, rand(43200, 86400));
 
         return $html;
     }