diff --git a/geometry/line_segment_intersection.cpp b/geometry/line_segment_intersection.cpp
index d523ae0a4..c6a6bdacc 100644
--- a/geometry/line_segment_intersection.cpp
+++ b/geometry/line_segment_intersection.cpp
@@ -3,8 +3,9 @@
  * @brief check whether two line segments intersect each other
  * or not.
  */
-#include <algorithm>
-#include <iostream>
+#include <stdio.h>    // for printf
+#include <algorithm>  // for max, min
+#include <iostream>   // for basic_istream::operator>>, char_traits, basic_i...
 
 /**
  * Define a Point.