diff --git a/RTCP/Storage/include/Storage/FastFileStream.h b/RTCP/Storage/include/Storage/FastFileStream.h
index e2955c541d2e0473ef811f1acd01309d4aacad98..c4368dbd9cd011cc16125d0af58fa6b4bf0082c1 100644
--- a/RTCP/Storage/include/Storage/FastFileStream.h
+++ b/RTCP/Storage/include/Storage/FastFileStream.h
@@ -45,6 +45,8 @@ class FastFileStream : public FileStream
 
     virtual void skip( size_t bytes );
 
+    virtual size_t size();
+
     // formally, the required alignment for O_DIRECT is determined by the file system
     static const unsigned alignment = 512;
   private: