diff --git a/menu_block.module b/menu_block.module
index 738dac3..86de8f9 100644
--- a/menu_block.module
+++ b/menu_block.module
@@ -684,16 +684,23 @@ function menu_tree_prune_tree(array &$tree, $level, array $parent_item = NULL, $
     for ($i = 1; $i <= MENU_MAX_DEPTH && $parent_item["p$i"] != '0'; $i++) {
       $plid = $parent_item["p$i"];
       $found_active_trail = FALSE;
+      
       // Examine each element at this level for the ancestor.
       foreach ($tree as $key => &$value) {
         if ($tree[$key]['link']['mlid'] == $plid) {
           menu_block_set_title($tree[$key]['link']);
-          // Prune the tree to the children of this ancestor.
+          
           $found_active_trail = TRUE;
-          if (!empty($include_parent) && $plid != $parent_item['plid']) {
+          
+          // Check if this ancestor is indeed the parent of our starting level.
+          $is_parent = $plid != $parent_item['plid'] && $parent_item['depth'] == $i;
+          
+          if (!empty($include_parent) && $is_parent) {
+            // Prune the tree to this ancestor.
             $tree = array($key => $tree[$key]);
           }
           else {
+            // Prune the tree to the children of this ancestor.
             $tree = $tree[$key]['below'] ? $tree[$key]['below'] : array();
           }
           break;