diff -urNp lyx-2.3.4.2-orig/src/insets/ExternalTemplate.cpp lyx-2.3.4.2-dwok/src/insets/ExternalTemplate.cpp
--- lyx-2.3.4.2-orig/src/insets/ExternalTemplate.cpp	2020-05-13 20:35:18.478772790 +0200
+++ lyx-2.3.4.2-dwok/src/insets/ExternalTemplate.cpp	2020-05-13 20:35:55.100049358 +0200
@@ -22,6 +22,7 @@
 #include "support/PathChanger.h"
 #include "support/Translator.h"
 
+#include <algorithm>
 #include <ostream>
 
 using namespace std;