diff --git a/Ridges_3/examples/Ridges_3/PolyhedralSurf.h b/Ridges_3/examples/Ridges_3/PolyhedralSurf.h
index 2fddaca60c5..7cd1f077056 100644
--- a/Ridges_3/examples/Ridges_3/PolyhedralSurf.h
+++ b/Ridges_3/examples/Ridges_3/PolyhedralSurf.h
@@ -13,7 +13,6 @@
 #include <list>
 
 #include <boost/foreach.hpp>
-#include "PolyhedralSurf_operations.h"
 
 //----------------------------------------------------------------
 // A redefined items class for the Polyhedron_3 with