https://bugs.gentoo.org/672250

--- a/DipoleShower/Base/DipoleChain.cc
+++ b/DipoleShower/Base/DipoleChain.cc
@@ -15,6 +15,7 @@
 #include "Herwig++/DipoleShower/Utility/DipolePartonSplitter.h"
 
 #include <boost/utility.hpp>
+#include <boost/next_prior.hpp>
 
 using namespace Herwig;
 
--- a/DipoleShower/Base/DipoleEventRecord.cc
+++ b/DipoleShower/Base/DipoleEventRecord.cc
@@ -19,6 +19,7 @@
 #include "ThePEG/PDF/PartonExtractor.h"
 
 #include <boost/utility.hpp>
+#include <boost/next_prior.hpp>
 
 #include <algorithm>
 
--- a/Exsample2/BinnedStatistics.h
+++ b/Exsample2/BinnedStatistics.h
@@ -16,6 +16,7 @@
 #include "ThePEG/Repository/UseRandom.h"
 
 #include <boost/utility.hpp>
+#include <boost/next_prior.hpp>
 
 namespace Herwig {
 
--- a/Exsample2/exsample/config.h
+++ b/Exsample2/exsample/config.h
@@ -25,6 +25,7 @@
 #include <limits>
 
 #include <boost/utility.hpp>
+#include <boost/next_prior.hpp>
 #include <boost/scoped_array.hpp>
 #include <boost/scoped_ptr.hpp>