diff --git a/model/sync-leaf.h b/model/sync-leaf.h
index c4da60c..c5f4c20 100644
--- a/model/sync-leaf.h
+++ b/model/sync-leaf.h
@@ -41,7 +41,7 @@
    * @param seq  Initial sequence number of the pointer
    */
   Leaf (NameInfoConstPtr info, const SeqNo &seq);
-  virtual ~Leaf () { }
+  virtual ~Leaf () = 0;
   
   /**
    * @brief Get name of the leaf