diff --git a/include/boost/unordered/detail/implementation.hpp b/include/boost/unordered/detail/implementation.hpp
index 6876a57d..10c8806c 100644
--- a/include/boost/unordered/detail/implementation.hpp
+++ b/include/boost/unordered/detail/implementation.hpp
@@ -48,6 +48,7 @@
 #include <boost/type_traits/make_void.hpp>
 #include <boost/type_traits/remove_const.hpp>
 
+#include <algorithm>
 #include <cmath>
 #include <iterator>
 #include <stdexcept>