diff --git a/Distance_3/include/CGAL/squared_distance_3_0.h b/Distance_3/include/CGAL/squared_distance_3_0.h
index 7ec5e64337e..fe4b49edbfd 100644
--- a/Distance_3/include/CGAL/squared_distance_3_0.h
+++ b/Distance_3/include/CGAL/squared_distance_3_0.h
@@ -26,6 +26,7 @@
 #include <CGAL/Weighted_point_3.h>
 #include <CGAL/Vector_3.h>
 #include <CGAL/number_utils.h>
+#include <CGAL/Rational_traits.h>
 
 namespace CGAL {