diff --git a/core/includes/common.inc b/core/includes/common.inc
index 4843551..a01d47d 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -6094,9 +6094,10 @@ function drupal_render_cache_set(&$markup, $elements) {
   if ($attached) {
     $data['#attached'] = $attached;
   }
+  $tags = drupal_render_collect_cache_tags($elements, TRUE);
   $bin = isset($elements['#cache']['bin']) ? $elements['#cache']['bin'] : 'cache';
   $expire = isset($elements['#cache']['expire']) ? $elements['#cache']['expire'] : CACHE_PERMANENT;
-  cache($bin)->set($cid, $data, $expire);
+  cache($bin)->set($cid, $data, $expire, $tags);
 }
 
 /**
@@ -6143,6 +6144,57 @@ function drupal_render_collect_attached($elements, $return = FALSE) {
 }
 
 /**
+ * Collects cache tags for an element and its children into a single array.
+ *
+ * When caching elements, it is necessary to collect all cache tags into a 
+ * single array, from both the element itself and all child elements. This
+ * allows items to be invalidated based on all tags attached to the content
+ * they're constituted from. 
+ *
+ * @param $elements
+ *   The element to collect #cache_tags from.
+ * @param $return
+ *   Whether to return the attached elements and reset the internal static.
+ *
+ * @return
+ *   The #attached array for this element and its descendants.
+ */
+function drupal_render_collect_cache_tags($elements, $return = FALSE) {
+  $tags = &drupal_static(__FUNCTION__, array());
+
+  // Collect all #attached for this element.
+  if (isset($elements['#cache']['tags'])) {
+    foreach ($elements['#cache']['tags'] as $namespace => $values) {
+      if (is_array($values)) {
+        foreach ($values as $value) {
+          if (!isset($tags[$namespace][$value])) {
+            $tags[$namespace][$value] = $value;
+          }
+        }
+      }
+      else {
+        if (!isset($tags[$namespace])) { 
+          $tags[$namespace] = $values;
+        }
+      }
+    }
+  }
+  if ($children = element_children($elements)) {
+    foreach ($children as $child) {
+      drupal_render_collect_cache_tags($elements[$child]);
+    }
+  }
+
+  // If this was the first call to the function, return all attached elements
+  // and reset the static cache.
+  if ($return) {
+    $return = $tags;
+    $tags = array();
+    return $return;
+  }
+}
+
+/**
  * Prepares an element for caching based on a query.
  *
  * This smart caching strategy saves Drupal from querying and rendering to HTML