diff --git a/include/exiv2/basicio.hpp b/include/exiv2/basicio.hpp
index 65f49366..4deef29d 100644
--- a/include/exiv2/basicio.hpp
+++ b/include/exiv2/basicio.hpp
@@ -277,7 +277,7 @@ namespace Exiv2 {
         //! @name Creators
         //@{
         //! Default Constructor
-        BasicIo() {}
+        BasicIo() : bigBlock_(NULL) {};
         //@}
     }; // class BasicIo