diff --git a/src/libslic3r/GCode/ToolOrderUtils.hpp b/src/libslic3r/GCode/ToolOrderUtils.hpp
index a2da86b0d..26c9a0118 100644
--- a/src/libslic3r/GCode/ToolOrderUtils.hpp
+++ b/src/libslic3r/GCode/ToolOrderUtils.hpp
@@ -4,7 +4,9 @@
 #include <vector>
 #include <optional>
 #include <functional>
+#include <limits>
 #include <memory>
+#include <unordered_set>
 
 namespace Slic3r {