diff --git a/Triangulation_2/include/CGAL/Triangulation_2.h b/Triangulation_2/include/CGAL/Triangulation_2.h
index 2ee47f2f4ee..250cb8530b9 100644
--- a/Triangulation_2/include/CGAL/Triangulation_2.h
+++ b/Triangulation_2/include/CGAL/Triangulation_2.h
@@ -40,6 +40,7 @@
 #include <CGAL/Triangulation_face_base_2.h>
 #include <CGAL/Triangulation_line_face_circulator_2.h>
 #include <CGAL/spatial_sort.h>
+#include <CGAL/double.h>
 
 #include <boost/random/linear_congruential.hpp>
 #include <boost/random/uniform_smallint.hpp>