diff --git a/lib/src/bvh.rs b/lib/src/bvh.rs
index 14a0ec9..2f24212 100644
--- a/lib/src/bvh.rs
+++ b/lib/src/bvh.rs
@@ -119,7 +119,8 @@ impl Bvh{
 			let clamped_point=start_point.min(aabb.max()).max(aabb.min());
 			Some((start_point-clamped_point).length_squared())
 		};
-		let (_,event_slice)=self.bvh.traverse(start_point,Fixed::ZERO,Fixed::MAX,intersect_leaf,intersect_aabb)?;
+		// traverse uses strict `start_time < t`, so use NEG_EPSILON to keep exact-zero-distance hits.
+		let (_,event_slice)=self.bvh.traverse(start_point,Fixed::NEG_EPSILON,Fixed::MAX,intersect_leaf,intersect_aabb)?;
 
 		// find time at the closest point
 		let (best_time,mut best_distance)=output_events[event_slice.slice.start..event_slice.slice.end].iter().map(|event|{