diff --git a/src/libslic3r/Clipper2Utils.hpp b/src/libslic3r/Clipper2Utils.hpp
index f0756a238..402d43c7a 100644
--- a/src/libslic3r/Clipper2Utils.hpp
+++ b/src/libslic3r/Clipper2Utils.hpp
@@ -1,6 +1,7 @@
 #ifndef slic3r_Clipper2Utils_hpp_
 #define slic3r_Clipper2Utils_hpp_
 
+#include "ExPolygon.hpp"
 #include "Polygon.hpp"
 #include "Polyline.hpp"