diff --git a/Number_types/test/Number_types/to_interval_test.cpp b/Number_types/test/Number_types/to_interval_test.cpp
index 59752059bf6..69ae3969e5b 100644
--- a/Number_types/test/Number_types/to_interval_test.cpp
+++ b/Number_types/test/Number_types/to_interval_test.cpp
@@ -3,6 +3,9 @@
 #include <iostream>
 
 // That one should not be needed in the long term:
+#include <CGAL/double.h>
+#include <CGAL/float.h>
+#include <CGAL/int.h>
 #include <CGAL/Interval_nt.h>
 
 #ifdef CGAL_USE_LEDA