diff --git a/Cargo.toml b/Cargo.toml
index fb64861..e7b7c21 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ readme = "README.md"
 bevy = {version="0.9.1", features = ["bevy_render", "bevy_core_pipeline", "bevy_asset", "bevy_sprite", "render", "bevy_winit", "png", "x11"], default-features=false }
 bevy_egui = "0.17.1"
 bevy_pancam = { version = "0.7.0", features = ["bevy_egui"] }
-bevy_prototype_lyon = "0.7.1"
+bevy_prototype_lyon = "0.7.2"
 colorgrad = "0.6.2"
 itertools = "0.10.5"
 fastrand = "1.8.0"
diff --git a/src/aesthetics.rs b/src/aesthetics.rs
index 9439080..da7e0ab 100644
--- a/src/aesthetics.rs
+++ b/src/aesthetics.rs
@@ -287,7 +287,7 @@ fn build_axes(
                     transform.translation.y += arrow.direction.perp().y * away;
                     transform
                 };
-                let mut axis_entry = axes
+                let axis_entry = axes
                     .entry(arrow.id.clone())
                     .or_insert(HashMap::new())
                     .entry(geom.side.clone())
diff --git a/src/escher.rs b/src/escher.rs
index 4c26e45..32f6090 100644
--- a/src/escher.rs
+++ b/src/escher.rs
@@ -448,6 +448,7 @@ pub fn load_map(
         let ori: Vec2 = Vec2::new(ori.x, -ori.y);
         let direction = my_map.main_direction(&reac);
         let mut products = reac.get_products(&my_map.metabolism);
+        let mut arrow_heads = ShapePath::new();
         for (_, segment) in reac.segments.iter_mut() {
             if let (Some(from), Some(to)) = (
                 my_map.met_coords(&segment.from_node_id),
@@ -480,10 +481,11 @@ pub fn load_map(
                 if let Some((drawn, importance)) = products.get_mut(&segment.to_node_id) {
                     if !*drawn {
                         let offset = match importance {
-                            MetImportance::Primary => 20.0,
-                            MetImportance::Secondary => 12.0,
+                            MetImportance::Primary => 22.0,
+                            MetImportance::Secondary => 14.0,
                         };
-                        draw_arrow(&mut path_builder, last_from - ori, re_to - ori, offset);
+                        arrow_heads =
+                            arrow_heads.add(&draw_arrow(last_from - ori, re_to - ori, offset));
                         *drawn = true;
                     }
                 }
@@ -501,9 +503,11 @@ pub fn load_map(
             node_id,
             xlimits: None,
         };
+        let mut builder = GeometryBuilder::new();
+        builder = builder.add(&line);
+        builder = builder.add(&arrow_heads.build());
         commands.spawn((
-            GeometryBuilder::build_as(
-                &line,
+            builder.build(
                 DrawMode::Stroke(StrokeMode::new(ARROW_COLOR, 10.0)),
                 Transform::from_xyz(ori.x - center_x, ori.y + center_y, 1.),
             ),
diff --git a/src/funcplot.rs b/src/funcplot.rs
index 55ca57b..fa5ddb0 100644
--- a/src/funcplot.rs
+++ b/src/funcplot.rs
@@ -4,6 +4,7 @@ use bevy::prelude::{Color, Font, Handle, Text, Text2dBundle, TextStyle, Transfor
 use bevy_prototype_lyon::{
     entity::ShapeBundle,
     prelude::{DrawMode, GeometryBuilder, Path, PathBuilder, StrokeMode},
+    shapes,
 };
 use colorgrad::{Color as GradColor, CustomGradient, Gradient};
 
@@ -365,24 +366,12 @@ pub fn build_grad(
     .expect("no gradient")
 }
 
-fn arrow_head(from: Vec2, to: Vec2) -> (Vec2, Vec2) {
-    // triangle shape; hardcoded for now
-    const HEIGHT: f32 = 1.0;
-    const HALF_W: f32 = 14.0;
-    let u = (to - from) / (to - from).length();
-    let v = Vec2::new(-u.y, u.x);
-    (
-        (to - HEIGHT * u + HALF_W * v),
-        (to - HEIGHT * u - HALF_W * v),
-    )
-}
-
-pub fn draw_arrow(path: &mut PathBuilder, from: Vec2, to: Vec2, offset: f32) {
+pub fn draw_arrow(from: Vec2, to: Vec2, offset: f32) -> shapes::Circle {
     // with an offset to avoid being hidden by metabolites
     let u = (to - from) / (to - from).length();
     let to = to - offset * u;
-    let (left, right) = arrow_head(from, to);
-    path.move_to(right);
-    // path.line_to(to);
-    path.line_to(left);
+    shapes::Circle {
+        radius: 5.0,
+        center: to,
+    }
 }
diff --git a/src/scale.rs b/src/scale.rs
index ce93c72..e25f2b7 100644
--- a/src/scale.rs
+++ b/src/scale.rs
@@ -25,7 +25,7 @@ fn zoom_fonts(
         return;
     };
     for (mut text, def) in text_query.iter_mut() {
-        for mut section in text.sections.iter_mut() {
+        for section in text.sections.iter_mut() {
             let new_font_size = lerp(proj.scale, 1., 40., def.size, def.size * 10.);
             // step update to enhance perfomance
             if (new_font_size - section.style.font_size).abs() > 1.0 {