diff --git a/src/XrdS3/XrdS3Utils.cc b/src/XrdS3/XrdS3Utils.cc
index 48bd5d3307e..dcd1c964226 100644
--- a/src/XrdS3/XrdS3Utils.cc
+++ b/src/XrdS3/XrdS3Utils.cc
@@ -32,6 +32,7 @@
 #include <iomanip>
 #include <iostream>
 #include <sstream>
+#include <algorithm>
 //------------------------------------------------------------------------------
 #include "XrdPosix/XrdPosixExtern.hh"
 //------------------------------------------------------------------------------