diff --git a/geom/ray.hpp b/geom/ray.hpp
index e4a276a4..fabac6c0 100644
--- a/geom/ray.hpp
+++ b/geom/ray.hpp
@@ -109,7 +109,7 @@ namespace util::geom {
             return std::numeric_limits<T>::infinity ();
 
         // closest is behind us
-        if (tmax < 0)
+        if (tmin < 0)
             return tmax;
 
         // closest is in front of us