diff --git a/src/model_physics.rs b/src/model_physics.rs
index ef08ce7d..452ebcfd 100644
--- a/src/model_physics.rs
+++ b/src/model_physics.rs
@@ -451,9 +451,9 @@ impl MinkowskiMesh<'_>{
 					let face_n=self.face_nd(face_id).0;
 					//edge-face boundary nd, n facing out of the face towards the edge
 					let boundary_n=face_n.cross(edge_n)*(i as i64*2-1);
-					let boundary_d=boundary_n.dot(vert_sum);
+					let boundary_d=boundary_n.dot128(vert_sum);
 					// point.dot(boundary_n) is multiplied by two because vert_sum sums two vertices.
-					if infinity_dir.dot(boundary_n)==Planar64::ZERO&&point.dot(boundary_n)*2<=boundary_d{
+					if infinity_dir.dot(boundary_n)==Planar64::ZERO&&point.dot128(boundary_n)*2<=boundary_d{
 						//both faces cannot pass this condition, return early if one does.
 						return FEV::<MinkowskiFace,MinkowskiDirectedEdge,MinkowskiVert>::Face(face_id);
 					}