diff --git a/lru.h b/lru.h
index 85280b1fc..e6418c68b 100644
--- a/lru.h
+++ b/lru.h
@@ -36,6 +36,9 @@ public:
     /** Constructor */
     lru_node_t(const wcstring &pkey) : prev(NULL), next(NULL), key(pkey) { }
 
+    /** Virtual destructor that does nothing for classes that inherit lru_node_t */
+    virtual ~lru_node_t() {}
+
     /** operator< for std::set */
     bool operator<(const lru_node_t &other) const
     {