diff --git a/Spatial_searching/include/CGAL/Kd_tree.h b/Spatial_searching/include/CGAL/Kd_tree.h
index dc3be46d270..0156557ffca 100644
--- a/Spatial_searching/include/CGAL/Kd_tree.h
+++ b/Spatial_searching/include/CGAL/Kd_tree.h
@@ -23,7 +23,7 @@
 #include <vector>
 #include <string>
 #include <unordered_map>
-#include <fstream>
+#include <ostream>
 
 #include <CGAL/algorithm.h>
 #include <CGAL/Kd_tree_node.h>