diff --git a/geom/fwd.hpp b/geom/fwd.hpp
index 8761c350..3401e844 100644
--- a/geom/fwd.hpp
+++ b/geom/fwd.hpp
@@ -12,13 +12,14 @@
 #include <cstdlib>
 
 namespace cruft::geom {
-    template <size_t S, typename T> struct ray;
-    template <size_t S, typename T> struct plane;
     template <size_t S, typename T> struct aabb;
-    template <size_t S, typename T> struct sphere;
-    template <size_t S, typename T> struct ellipse;
-    template <size_t S, typename T> struct rect;
     template <size_t S, typename T> struct cylinder;
+    template <size_t S, typename T> struct ellipse;
+    template <size_t S, typename T> struct plane;
+    template <size_t S, typename T> struct ray;
+    template <size_t S, typename T> struct rect;
+    template <size_t S, typename T> struct segment;
+    template <size_t S, typename T> struct sphere;
     template <size_t S, typename T> struct tri;
 
     template <typename T> struct frustum;
diff --git a/geom/iostream.cpp b/geom/iostream.cpp
index 5529b094..ae6d6349 100644
--- a/geom/iostream.cpp
+++ b/geom/iostream.cpp
@@ -8,9 +8,11 @@
 
 #include "iostream.hpp"
 
-#include "sphere.hpp"
-#include "plane.hpp"
 #include "frustum.hpp"
+#include "plane.hpp"
+#include "segment.hpp"
+#include "sphere.hpp"
+
 #include "../coord/iostream.hpp"
 
 
@@ -28,6 +30,19 @@ template std::ostream& cruft::geom::operator<< (std::ostream&, cruft::geom::sphe
 template std::ostream& cruft::geom::operator<< (std::ostream&, cruft::geom::sphere<3,float>);
 
 
+///////////////////////////////////////////////////////////////////////////////
+template <size_t S, typename T>
+std::ostream&
+cruft::geom::operator<< (std::ostream &os, cruft::geom::segment<S,T> const &val)
+{
+    return os << "[ " << val.a << ", " << val.b << " ]";
+}
+
+
+template std::ostream& cruft::geom::operator<< (std::ostream&, cruft::geom::segment2i const&);
+template std::ostream& cruft::geom::operator<< (std::ostream&, cruft::geom::segment2f const&);
+
+
 ///////////////////////////////////////////////////////////////////////////////
 template <size_t S, typename T>
 std::ostream&
diff --git a/geom/iostream.hpp b/geom/iostream.hpp
index 099fa39f..72b1534e 100644
--- a/geom/iostream.hpp
+++ b/geom/iostream.hpp
@@ -3,11 +3,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  *
- * Copyright 2015-2018 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2015-2019 Danny Robson <danny@nerdcruft.net>
  */
 
-#ifndef CRUFT_UTIL_GEOM_IOSTREAM_HPP
-#define CRUFT_UTIL_GEOM_IOSTREAM_HPP
+#pragma once
 
 #include "fwd.hpp"
 
@@ -20,6 +19,10 @@ namespace cruft::geom {
     std::ostream&
     operator<< (std::ostream&, aabb<S,T>);
 
+    template <size_t S, typename T>
+    std::ostream&
+    operator<< (std::ostream&, segment<S,T> const&);
+
     template <size_t S, typename T>
     std::ostream&
     operator<< (std::ostream&, ray<S,T>);
@@ -36,5 +39,3 @@ namespace cruft::geom {
     std::ostream&
     operator<< (std::ostream&, frustum<T>);
 }
-
-#endif