diff --git a/crates/effects/src/stylize3.rs b/crates/effects/src/stylize3.rs
index 403c325cd..e28f9a4fa 100644
--- a/crates/effects/src/stylize3.rs
+++ b/crates/effects/src/stylize3.rs
@@ -351,7 +351,7 @@ fn hex_cell(x: f64, y: f64, r: f64) -> ((f64, f64), (i64, i64)) {
     let rr = (2.0 / 3.0 * y) / r;
     // Cube rounding.
     let (cx, cz) = (q, rr);
-    let cy = -cx - cz;
+    let cy = (-3f64.sqrt() / 3.0 * x - y / 3.0) / r;
     let (mut rx, ry, mut rz) = (cx.round(), cy.round(), cz.round());
     let (dx, dy, dz) = ((rx - cx).abs(), (ry - cy).abs(), (rz - cz).abs());
     if dx > dy && dx > dz {
diff --git a/crates/gpu/src/shaders/fx_pixel2.wgsl b/crates/gpu/src/shaders/fx_pixel2.wgsl
index a63a91fed..2c6f5e50c 100644
--- a/crates/gpu/src/shaders/fx_pixel2.wgsl
+++ b/crates/gpu/src/shaders/fx_pixel2.wgsl
@@ -647,7 +647,9 @@ fn fp2_hextile(@builtin(global_invocation_id) gid: vec3<u32>) {
     // stylize3::hex_cell (cube rounding).
     let q = (0.5773502691896257 * u - v / 3.0) / r;
     let rr = (2.0 / 3.0 * v) / r;
-    let ccy = -q - rr;
+    // Evaluate the third cube coordinate symmetrically with q so the centerline
+    // tie is not broken by subtracting separately rounded coordinates.
+    let ccy = (-0.5773502691896257 * u - v / 3.0) / r;
     var rx = round_away(q);
     let ry = round_away(ccy);
     var rz = round_away(rr);