diff --git a/beast/module/core/containers/ElementComparator.h b/beast/module/core/containers/ElementComparator.h
index c683f2db4..61f5d25f9 100644
--- a/beast/module/core/containers/ElementComparator.h
+++ b/beast/module/core/containers/ElementComparator.h
@@ -24,8 +24,9 @@
 #ifndef BEAST_MODULE_CORE_CONTAINERS_ELEMENTCOMPARATOR_H_INCLUDED
 #define BEAST_MODULE_CORE_CONTAINERS_ELEMENTCOMPARATOR_H_INCLUDED
 
-namespace beast
-{
+#include <algorithm>
+
+namespace beast {
 
 #ifndef DOXYGEN