diff --git a/Classification/include/CGAL/Classification/ETHZ/internal/random-forest/forest.hpp b/Classification/include/CGAL/Classification/ETHZ/internal/random-forest/forest.hpp
index 02d326f8c76..db51011e714 100644
--- a/Classification/include/CGAL/Classification/ETHZ/internal/random-forest/forest.hpp
+++ b/Classification/include/CGAL/Classification/ETHZ/internal/random-forest/forest.hpp
@@ -45,6 +45,8 @@
 #include <cstdio>
 #endif
 
+#include <algorithm>
+
 #include <CGAL/tags.h>
 
 #ifdef CGAL_LINKED_WITH_TBB