diff --git a/crates/ui-egui/src/panels/artboards.rs b/crates/ui-egui/src/panels/artboards.rs
index deff9d872..54a90ddc7 100644
--- a/crates/ui-egui/src/panels/artboards.rs
+++ b/crates/ui-egui/src/panels/artboards.rs
@@ -100,10 +100,12 @@ pub(crate) fn control_bar(app: &mut VectorcraftApp, ui: &mut Ui) -> bool {
     super::transform::reference_locator(ui, refi);
     let link = super::transform::proportional(app, ui);
     let rp = vectorcraft_geom::reference_point(r, refi);
+    // The W/H link sits between W and H, but is made after H so Tab goes from W straight to H and
+    // finds the link after it, as in the object Control bar.
+    let mut link_room = None;
     for (k, lbl, v) in [("x", "X:", rp.x - origin.x), ("y", "Y:", rp.y - origin.y), ("width", "W:", r.width()), ("height", "H:", r.height())] {
-        // The W/H link sits between W and H.
         if k == "height" {
-            super::transform::constrain_link(app, ui);
+            link_room = Some(super::transform::constrain_link_room(ui));
         }
         widgets::field_label(ui, egui::RichText::new(tl!(lbl)).size(12.0).color(t.text_dim));
         let set = if matches!(k, "width" | "height") {
@@ -121,6 +123,10 @@ pub(crate) fn control_bar(app: &mut VectorcraftApp, ui: &mut Ui) -> bool {
             super::transform::set_artboard(app, i, refi, xywh, link);
         }
     }
+    if let Some(room) = link_room {
+        let id = ui.scope_id().with("cb-ab-constrain-link");
+        super::transform::constrain_link_at(app, ui, ui.interact(room, id, egui::Sense::click()));
+    }
     true
 }
 
diff --git a/crates/ui-egui/src/panels/tests_constrain.rs b/crates/ui-egui/src/panels/tests_constrain.rs
index ea9ceec27..b5e8ed7f7 100644
--- a/crates/ui-egui/src/panels/tests_constrain.rs
+++ b/crates/ui-egui/src/panels/tests_constrain.rs
@@ -322,6 +322,12 @@ fn one_tab_moves_from_a_field_to_the_next() {
     let mut app = rect_app();
     tab_then_type(&mut app, crate::chrome::control_bar, "100 pt", "200");
     assert_eq!(size(&app), (100.0, 200.0), "Control bar: Tab went from W to H");
+    // The Artboard tool's Control bar puts the link after its fields too: Tab goes from W to H.
+    let mut app = rect_app();
+    app.select_tool("artboard");
+    tab_then_type(&mut app, crate::chrome::control_bar, "400 pt", "200");
+    let r = app.session.doc().unwrap().doc.artboards[0].rect;
+    assert_eq!((r.width().round(), r.height().round()), (400.0, 200.0), "Artboard Control bar: Tab went from W to H");
     // Shift+Tab goes back one field, one press too: from W to X in the panels.
     for (name, draw) in [("Transform panel", transform::show as Draw), ("Properties", properties::transform_section as Draw)] {
         let mut app = rect_app();
@@ -356,6 +362,16 @@ fn the_control_bar_link_toggles_by_click() {
         frame(&mut app, events);
     }
     assert!(app.session.prefs.constrain_proportions, "the click toggled the link");
+    // Tab from H finds the link, and Space or Enter toggles it, as a dialog's button takes them.
+    let h = at("50 pt").center();
+    let button = |pos, pressed| Event::PointerButton { pos, button: PointerButton::Primary, pressed, modifiers: Modifiers::NONE };
+    let tab = Event::Key { key: Key::Tab, physical_key: None, pressed: true, repeat: false, modifiers: Modifiers::NONE };
+    let enter = Event::Key { key: Key::Enter, physical_key: None, pressed: true, repeat: false, modifiers: Modifiers::NONE };
+    for events in [vec![Event::PointerMoved(h), button(h, true), button(h, false)], vec![], vec![tab], vec![], vec![enter], vec![]] {
+        frame(&mut app, events);
+    }
+    assert!(!app.session.prefs.constrain_proportions, "Enter on the focused link toggled it");
+    assert_eq!(size(&app), (100.0, 50.0), "and the fields kept their values");
 }
 
 /// Type `value` into the field of what `draw` shows that shows `field` after one Tab, and press
diff --git a/crates/ui-egui/src/panels/transform.rs b/crates/ui-egui/src/panels/transform.rs
index 815b5c4a8..ee3ce335c 100644
--- a/crates/ui-egui/src/panels/transform.rs
+++ b/crates/ui-egui/src/panels/transform.rs
@@ -492,11 +492,14 @@ pub fn constrain_link(app: &mut VectorcraftApp, ui: &mut Ui) {
 }
 
 /// [`constrain_link`]'s toggle, made over `at`: the Control bar keeps the link's place between W
-/// and H but makes it after H, so Tab goes from W straight to H and finds the link after it.
+/// and H but makes it after H, so Tab goes from W straight to H and finds the link after it. With
+/// the keyboard on it, Space or Enter toggles it, as a dialog's button takes them.
 pub fn constrain_link_at(app: &mut VectorcraftApp, ui: &mut Ui, at: egui::Response) {
     let on = app.session.prefs.constrain_proportions;
     let tip = tl!("Constrain Width and Height Proportions");
-    if widgets::paint_icon_button(ui, at, if on { "link" } else { "link-2-off" }, tip, on).clicked() {
+    let keyed = at.has_focus()
+        && ui.input_mut(|i| i.consume_key(egui::Modifiers::NONE, egui::Key::Space) | i.consume_key(egui::Modifiers::NONE, egui::Key::Enter));
+    if widgets::paint_icon_button(ui, at, if on { "link" } else { "link-2-off" }, tip, on).clicked() || keyed {
         set_pref(app, "constrainProportions", !on);
     }
 }