diff --git a/include/json/reader.h b/include/json/reader.h
index 728b35e..f8c3186 100644
--- a/include/json/reader.h
+++ b/include/json/reader.h
@@ -270,6 +270,7 @@ public:
 
   class Factory {
   public:
+    virtual ~Factory() {}
     /** \brief Allocate a CharReader via operator new().
      * \throw std::exception if something goes wrong (e.g. invalid settings)
      */