diff --git a/geom/segment.hpp b/geom/segment.hpp
index 0cb77b5e..9dd8f860 100644
--- a/geom/segment.hpp
+++ b/geom/segment.hpp
@@ -88,4 +88,8 @@ namespace cruft::geom {
 
     using segment2f = segment<2,float>;
     using segment3f = segment<3,float>;
+
+
+    template <size_t S, typename T>
+    segment (point<S,T>, point<S,T>) -> segment<S,T>;
 }