diff --git a/crates/chart/src/render.rs b/crates/chart/src/render.rs
index 63d30d9..0e4ebfd 100644
--- a/crates/chart/src/render.rs
+++ b/crates/chart/src/render.rs
@@ -266,8 +266,8 @@ fn draw_kind(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx) {
                 Scatter | ScatterLines | Bubble => scatter(ctx, chart, data, area),
                 Histogram => histogram(ctx, chart, data, area),
                 Waterfall => waterfall(ctx, chart, data, area),
-                BoxWhisker => box_whisker(ctx, data, area),
-                Stock => stock(ctx, data, area),
+                BoxWhisker => box_whisker(ctx, chart, data, area),
+                Stock => stock(ctx, chart, data, area),
                 _ => cartesian(ctx, chart, data, area, false),
             }
         }
@@ -1557,12 +1557,12 @@ fn quantile(sorted: &[f64], q: f64) -> f64 {
     a + (b - a) * frac
 }
 
-fn box_whisker(ctx: &mut Ctx, data: &ChartData, area: Bx) {
+fn box_whisker(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx) {
     let labels: Vec<String> = data.series.iter().map(|s| s.name.clone()).collect();
     let Some((lo, hi)) = value_range(data.series.iter().flat_map(|s| s.values.iter().flatten().copied())) else { return };
     let ys = nice_scale(lo, hi, false);
     let f = Fmt::new(data.series.first().map(|s| s.number_format.as_str()).unwrap_or("General"));
-    let plot = frame(ctx, area, CatAxis::Labels(&labels), &ValAxis { scale: ys, fmt: &f }, None, false, true);
+    let plot = frame(ctx, area, CatAxis::Labels(&labels), &ValAxis { scale: ys, fmt: &f }, None, false, chart.gridlines);
     if !plot.ok() {
         return;
     }
@@ -1601,7 +1601,7 @@ fn box_whisker(ctx: &mut Ctx, data: &ChartData, area: Bx) {
 
 // ---------------------------------------------------------------- stock
 
-fn stock(ctx: &mut Ctx, data: &ChartData, area: Bx) {
+fn stock(ctx: &mut Ctx, chart: &Chart, data: &ChartData, area: Bx) {
     let ncat = data.categories.len().max(data.series.iter().map(|s| s.values.len()).max().unwrap_or(0)).min(MAX_CATS);
     if ncat == 0 {
         return;
@@ -1610,7 +1610,7 @@ fn stock(ctx: &mut Ctx, data: &ChartData, area: Bx) {
     let Some((lo, hi)) = value_range(data.series.iter().flat_map(|s| s.values.iter().flatten().copied())) else { return };
     let ys = nice_scale(lo, hi, false);
     let f = Fmt::new(data.series.first().map(|s| s.number_format.as_str()).unwrap_or("General"));
-    let plot = frame(ctx, area, CatAxis::Labels(&labels), &ValAxis { scale: ys, fmt: &f }, None, false, true);
+    let plot = frame(ctx, area, CatAxis::Labels(&labels), &ValAxis { scale: ys, fmt: &f }, None, false, chart.gridlines);
     if !plot.ok() {
         return;
     }
diff --git a/crates/chart/src/tests.rs b/crates/chart/src/tests.rs
index a942677..db821b7 100644
--- a/crates/chart/src/tests.rs
+++ b/crates/chart/src/tests.rs
@@ -902,3 +902,24 @@ fn union_series_references() {
     c.series[0].values = format!("{}Sheet1!$B$1,Sheet1!$B$2{}", "(".repeat(5000), ")".repeat(5000));
     let _ = resolve(&wb, 0, &c);
 }
+
+#[test]
+fn box_and_stock_charts_honour_the_gridlines_flag() {
+    // Horizontal full-width lines in the gridline colour are the value-axis gridlines.
+    let grid: Rgba = [217, 217, 217, 255];
+    let is_grid = |p: &Prim| match p {
+        Prim::Line { color, pts, .. } => *color == grid && pts.len() == 2 && pts[0][1] == pts[1][1] && pts[1][0] - pts[0][0] > 200.0,
+        _ => false,
+    };
+    let grids = |prims: &[Prim]| prims.iter().filter(|p| is_grid(p)).count();
+    for kind in [ChartKind::BoxWhisker, ChartKind::Stock, ChartKind::ColumnClustered] {
+        let mut d = sample(kind);
+        d.series.push(series("Close", &[10000.0, 12000.0, 9000.0, 14000.0, 20000.0, 16000.0], [90, 90, 90, 255], kind));
+        let mut c = chart(kind);
+        let on = render(&c, &d, 500.0, 350.0, &ApproxMeasure);
+        c.gridlines = false;
+        let off = render(&c, &d, 500.0, 350.0, &ApproxMeasure);
+        assert!(grids(&on) > 0, "{kind:?}: gridlines on must draw lines");
+        assert_eq!(grids(&off), 0, "{kind:?}: gridlines off must hide them");
+    }
+}