diff --git a/shell/Ui/PanelSlider.qml b/shell/Ui/PanelSlider.qml
index d7bf1303b43..94b7a33e898 100644
--- a/shell/Ui/PanelSlider.qml
+++ b/shell/Ui/PanelSlider.qml
@@ -25,6 +25,13 @@ Item {
   property int tickCount: 0
   property color tickColor: bar ? bar.background : Color.background
 
+  // Corner rounding for the three drawn parts. The defaults are the pill shape
+  // the panels have always used; a caller that wants square controls sets them
+  // to 0 rather than copying this component.
+  property real trackRadius: trackHeight / 2
+  property real tickRadius: 1
+  property real knobRadius: knobSize / 2
+
   onValueChanged: if (!dragging) liveValue = value
 
   signal moved(real value)
@@ -47,7 +54,7 @@ Item {
     anchors.left: parent.left
     anchors.right: parent.right
     height: root.trackHeight
-    radius: height / 2
+    radius: root.trackRadius
     color: root.trackColor
   }
 
@@ -72,7 +79,7 @@ Item {
       required property int index
       width: Math.max(1, Style.space(2))
       height: root.trackHeight + Style.space(4)
-      radius: 1
+      radius: root.tickRadius
       color: root.tickColor
       anchors.verticalCenter: track.verticalCenter
       x: Math.max(0, Math.min(track.width - width,
@@ -84,7 +91,7 @@ Item {
     id: knob
     width: root.knobSize
     height: root.knobSize
-    radius: root.knobSize / 2
+    radius: root.knobRadius
     color: root.knobColor
     borderSpec: Border.flat(root.bar ? root.bar.background : "#101315", Math.max(1, Style.space(2)))
     anchors.verticalCenter: track.verticalCenter
diff --git a/test/shell.d/panel-slider-radius-test.sh b/test/shell.d/panel-slider-radius-test.sh
new file mode 100644
index 00000000000..6ea6e5f12ce
--- /dev/null
+++ b/test/shell.d/panel-slider-radius-test.sh
@@ -0,0 +1,140 @@
+#!/bin/bash
+source "$(dirname "$0")/base-test.sh"
+
+run_node_test <<'JS'
+const fs = require('fs')
+
+const sliderQml = fs.readFileSync(path.join(root, 'shell/Ui/PanelSlider.qml'), 'utf8')
+
+assert(
+  /property real trackRadius:\s*trackHeight \/ 2/.test(sliderQml) &&
+    /property real tickRadius:\s*1/.test(sliderQml) &&
+    /property real knobRadius:\s*knobSize \/ 2/.test(sliderQml),
+  'PanelSlider radius defaults reproduce the pill shape callers already render'
+)
+
+assert(
+  !/radius:\s*height \/ 2/.test(sliderQml) && !/radius:\s*root\.knobSize \/ 2/.test(sliderQml),
+  'PanelSlider draws from the radius properties instead of hardcoded expressions'
+)
+JS
+
+require_compositor "PanelSlider radius runtime test"
+
+if ! command -v quickshell >/dev/null 2>&1; then
+  pass "quickshell not installed; skipping PanelSlider radius runtime test"
+  exit 0
+fi
+
+TMPDIR=$(mktemp -d)
+cleanup() {
+  if [[ -d $TMPDIR ]]; then
+    rm -rf "$TMPDIR"
+  fi
+}
+trap cleanup EXIT
+
+ln -s "$ROOT/shell/Ui" "$TMPDIR/Ui"
+ln -s "$ROOT/shell/Commons" "$TMPDIR/Commons"
+
+cat >"$TMPDIR/shell.qml" <<'QML'
+import QtQuick
+import Quickshell
+import qs.Commons
+import qs.Ui
+
+ShellRoot {
+  id: root
+
+  function fail(message) {
+    console.log("RESULT fail " + message)
+    Qt.quit()
+  }
+
+  // Track, fill, ticks and knob are internal, so collect every drawn radius
+  // rather than depending on the order children happen to be declared in.
+  function drawnRadii(item, out) {
+    for (var i = 0; i < item.children.length; i++) {
+      var child = item.children[i]
+      if (child.radius !== undefined) out.push(child.radius)
+      root.drawnRadii(child, out)
+    }
+    return out
+  }
+
+  function runChecks() {
+    if (defaultSlider.trackRadius !== defaultSlider.trackHeight / 2) {
+      root.fail("default trackRadius is " + defaultSlider.trackRadius + ", expected " + defaultSlider.trackHeight / 2)
+      return
+    }
+    if (defaultSlider.knobRadius !== defaultSlider.knobSize / 2) {
+      root.fail("default knobRadius is " + defaultSlider.knobRadius + ", expected " + defaultSlider.knobSize / 2)
+      return
+    }
+    if (defaultSlider.tickRadius !== 1) {
+      root.fail("default tickRadius is " + defaultSlider.tickRadius + ", expected 1")
+      return
+    }
+
+    var rounded = root.drawnRadii(defaultSlider, [])
+    if (rounded.length === 0) {
+      root.fail("default slider drew nothing with a radius")
+      return
+    }
+    for (var i = 0; i < rounded.length; i++) {
+      if (rounded[i] <= 0) {
+        root.fail("default slider drew a square corner: radius " + rounded[i])
+        return
+      }
+    }
+
+    var squared = root.drawnRadii(squaredSlider, [])
+    if (squared.length !== rounded.length) {
+      root.fail("squared slider drew " + squared.length + " radii, default drew " + rounded.length)
+      return
+    }
+    for (var j = 0; j < squared.length; j++) {
+      if (squared[j] !== 0) {
+        root.fail("squared slider kept a rounded corner: radius " + squared[j])
+        return
+      }
+    }
+
+    console.log("RESULT pass")
+    Qt.quit()
+  }
+
+  Component.onCompleted: Qt.callLater(runChecks)
+
+  Item {
+    PanelSlider {
+      id: defaultSlider
+      width: 200
+      value: 0.5
+      tickCount: 5
+    }
+
+    PanelSlider {
+      id: squaredSlider
+      width: 200
+      value: 0.5
+      tickCount: 5
+      trackRadius: 0
+      tickRadius: 0
+      knobRadius: 0
+    }
+  }
+}
+QML
+
+output=$(timeout 15 quickshell -p "$TMPDIR" --no-color 2>&1) || {
+  printf '%s\n' "$output" >&2
+  fail "PanelSlider radius runtime fixture exits cleanly"
+}
+
+if ! grep -q "RESULT pass" <<<"$output"; then
+  printf '%s\n' "$output" >&2
+  fail "PanelSlider radius properties drive the drawn corners"
+fi
+
+pass "PanelSlider radius properties drive the drawn corners"