diff --git a/beast/module/core/text/LexicalCast.h b/beast/module/core/text/LexicalCast.h
index c83fdda4..59b481eb 100644
--- a/beast/module/core/text/LexicalCast.h
+++ b/beast/module/core/text/LexicalCast.h
@@ -22,7 +22,7 @@
 
 #include <beast/Config.h>
 #include <beast/cxx14/type_traits.h> // <type_traits>
-
+#include <algorithm>
 #include <cerrno>
 #include <cstdlib>
 #include <limits>