diff --git a/src/libslic3r/GCode/RetractWhenCrossingPerimeters.cpp b/src/libslic3r/GCode/RetractWhenCrossingPerimeters.cpp
index ebeca40cf3..3043e091b5 100644
--- a/src/libslic3r/GCode/RetractWhenCrossingPerimeters.cpp
+++ b/src/libslic3r/GCode/RetractWhenCrossingPerimeters.cpp
@@ -1,3 +1,4 @@
+#include "../ClipperUtils.hpp"
 #include "../Layer.hpp"
 
 #include "RetractWhenCrossingPerimeters.hpp"