diff --git a/src/ENDFtk/section/6.hpp b/src/ENDFtk/section/6.hpp
index fff6dd3a..5611ea43 100644
--- a/src/ENDFtk/section/6.hpp
+++ b/src/ENDFtk/section/6.hpp
@@ -5,7 +5,6 @@
 #include <complex>
 
 // other includes
-//#include "range/v3/algorithm/find_if_not.hpp"
 #include "range/v3/range/conversion.hpp"
 #include "range/v3/view/all.hpp"
 #include "range/v3/view/chunk.hpp"