diff --git a/Libraries/LibWeb/TreeNode.h b/Libraries/LibWeb/TreeNode.h
index 3cd47421373..96e8155b612 100644
--- a/Libraries/LibWeb/TreeNode.h
+++ b/Libraries/LibWeb/TreeNode.h
@@ -380,6 +380,8 @@ inline void TreeNode<T>::insert_before(NonnullRefPtr<T> node, RefPtr<T> child, b
     node->m_previous_sibling = child->m_previous_sibling;
     node->m_next_sibling = child;
 
+    child->m_previous_sibling = node;
+
     if (m_first_child == child)
         m_first_child = node;