diff --git a/src/opt/hdf5/lib/h5_content_base.cc b/src/opt/hdf5/lib/h5_content_base.cc
index 8a7a1b3..acf86d3 100644
--- a/src/opt/hdf5/lib/h5_content_base.cc
+++ b/src/opt/hdf5/lib/h5_content_base.cc
@@ -36,7 +36,7 @@ namespace CNORXZ
 	    return mId;
 	}
 
-	bool isOpen() const
+	bool ContentBase::isOpen() const
 	{
 	    return mId != 0;
 	}