diff --git a/Distance_3/include/CGAL/Distance_3/Point_3_Point_3.h b/Distance_3/include/CGAL/Distance_3/Point_3_Point_3.h
index 088e28b08d6..4b53dc99676 100644
--- a/Distance_3/include/CGAL/Distance_3/Point_3_Point_3.h
+++ b/Distance_3/include/CGAL/Distance_3/Point_3_Point_3.h
@@ -17,6 +17,7 @@
 #ifndef CGAL_DISTANCE_3_POINT_3_POINT_3_H
 #define CGAL_DISTANCE_3_POINT_3_POINT_3_H
 
+#include <CGAL/number_utils.h>
 #include <CGAL/Point_3.h>
 
 namespace CGAL {