diff --git a/include/boost/algorithm/algorithm.hpp b/include/boost/algorithm/algorithm.hpp
index 0cf6c45..a3a6bee 100644
--- a/include/boost/algorithm/algorithm.hpp
+++ b/include/boost/algorithm/algorithm.hpp
@@ -17,6 +17,8 @@
 #ifndef BOOST_ALGORITHM_HPP
 #define BOOST_ALGORITHM_HPP
 
+#include <functional> // for plus and multiplies
+
 #include <boost/utility/enable_if.hpp> // for boost::disable_if
 #include <boost/type_traits/is_integral.hpp>