diff --git a/AGENTS.md b/AGENTS.md
index c9a44d8..c146040 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -65,7 +65,7 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - The macOS open panel runs out of process too. Escape does not reach it; the harness sends it `cancel:`.
 - gpui's `test-support` swaps its executor: `block` fails on a real dispatcher. It stays behind this crate's `test-support` feature, never on for the gallery.
 - A tracked `FocusHandle` is a Tab stop only when built with `.tab_stop(true)`. `tab_index` on the div reaches only handles gpui makes itself. `primitives::tab_stop` keeps one per id.
-- Floating lists go below their anchor, or above when only above has room (`forms::options::float`). gpui's own switch keeps the anchor point, so a flipped list would cover its trigger.
+- Floating lists go below their anchor, or above when only above has room (`forms::options::float`). gpui's own switch keeps the anchor point, so a flipped list would cover its trigger. An option list is at least its trigger's width and at most the window's less `window_margin` each side, so gpui can snap it inside and its rows end in an ellipsis; wider, gpui pins it left and the rest runs off.
 - A trigger that opens a list goes through `forms::select::listing`: toggle, keys, blur and popup live there, for Select, TabOverflowMenu and Breadcrumb alike.
 - A palette goes through `navigation::palette::Palette`: query field, grouped rows, cursor, keys and focus live there. CommandPalette, QuickOpen, QuickSwitcher, SearchPalette and QuickLauncher only build rows.
 - A menu goes through `menus::menu`: rows, submenus, keys, focus and presses outside live there, for DropdownMenu, OverflowMenu, SplitButton, ContextMenu, SearchableMenu and MenuBar. A press on the host's own box is the host's to handle, so a trigger toggles and a right click moves a context menu without a close and reopen in one event.
diff --git a/TASKS.md b/TASKS.md
index 01c0a1a..5a4269c 100644
--- a/TASKS.md
+++ b/TASKS.md
@@ -316,3 +316,4 @@ Per-component lines live in `tasks/`. Tags there:
 | T26c | 3 | PASS | |
 | T26d | 1 | FAIL | the playlist's keys started from the first row, not the song under way; the waveform's bar fit sat untested in paint |
 | T26d | 2 | PASS | |
+| T26e | 1 | FAIL | an option list had no width limit, so a long device name ran it past the window |
diff --git a/src/forms/options.rs b/src/forms/options.rs
index 4361da1..3a3bbdb 100644
--- a/src/forms/options.rs
+++ b/src/forms/options.rs
@@ -286,10 +286,12 @@ impl Popup<'_> {
             })
         });
         let list = surface(self.id, cx)
+            .debug_selector(|| "option-list".into())
             .min_w(theme.tooltip_max_width())
             .when(anchor.size.width > Pixels::ZERO, |list| {
                 list.min_w(anchor.size.width)
             })
+            .max_w(window.viewport_size().width - theme.window_margin() * 2.0)
             .max_h(theme.list_max_height())
             .overflow_y_scroll()
             .when_some(self.scroll, |list, handle| list.track_scroll(handle))
diff --git a/src/forms/tests/choices.rs b/src/forms/tests/choices.rs
index 4b8e72b..0e544ab 100644
--- a/src/forms/tests/choices.rs
+++ b/src/forms/tests/choices.rs
@@ -446,3 +446,32 @@ fn an_open_select_with_nothing_to_pick_fails(cx: &mut TestAppContext) {
     setup(cx);
     cx.add_window_view(|_, _| Empty(false));
 }
+
+/// A select whose one choice runs long.
+struct Named;
+
+impl Render for Named {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let long = Choice::new("long", "A very long microphone name that runs past the box");
+        div()
+            .w(px(200.0))
+            .child(Select::new("long", [long, Choice::new("b", "B")]))
+    }
+}
+
+#[gpui::test]
+fn a_long_choice_keeps_its_list_inside_the_window(cx: &mut TestAppContext) {
+    setup(cx);
+    let (_, cx) = cx.add_window_view(|_, _| Named);
+    cx.simulate_resize(gpui::size(px(280.0), px(600.0)));
+    cx.run_until_parked();
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("enter");
+    release("enter", cx);
+    cx.run_until_parked();
+    let list = cx.debug_bounds("option-list").expect("the list opens");
+    assert!(
+        list.left() >= px(0.0) && list.right() <= px(280.0),
+        "{list:?}"
+    );
+}
diff --git a/src/media/camera.rs b/src/media/camera.rs
index 53e8004..cf0b480 100644
--- a/src/media/camera.rs
+++ b/src/media/camera.rs
@@ -7,7 +7,7 @@ use gpui::{
 
 use crate::{
     forms::{Choice, OnValue, Select},
-    primitives::{Icon, IconName, framed},
+    primitives::{Icon, IconName, checked_ratio, framed},
     theme::{ActiveTheme, IconSize, Radius, TextSize},
     typography::Ellipsis,
 };
@@ -24,10 +24,9 @@ pub struct CameraPreview {
 impl CameraPreview {
     /// `ratio` is the camera's width over its height.
     pub fn new(id: impl Into<ElementId>, ratio: f32) -> Self {
-        assert!(ratio > 0.0, "a camera's shape of {ratio}");
         Self {
             id: id.into(),
-            ratio,
+            ratio: checked_ratio(ratio),
             frame: None,
             name: None,
         }
diff --git a/src/media/model.rs b/src/media/model.rs
index 488fd95..37fc3fa 100644
--- a/src/media/model.rs
+++ b/src/media/model.rs
@@ -11,7 +11,7 @@ use crate::{
     layout::seeded::use_seeded,
     motion::Spinner,
     overlays::media_button,
-    primitives::{FocusRing, IconName, framed, tab_stop},
+    primitives::{FocusRing, IconName, checked_ratio, framed, tab_stop},
     theme::{ActiveTheme, ControlSize, Radius},
 };
 
@@ -70,7 +70,6 @@ pub struct ModelViewer {
 impl ModelViewer {
     /// `ratio` is the view's width over its height.
     pub fn new(id: impl Into<ElementId>, ratio: f32, orbit: Orbit) -> Self {
-        assert!(ratio > 0.0, "a view's shape of {ratio}");
         assert!(
             (NEAR..=FAR).contains(&orbit.distance),
             "a distance of {}",
@@ -78,7 +77,7 @@ impl ModelViewer {
         );
         Self {
             id: id.into(),
-            ratio,
+            ratio: checked_ratio(ratio),
             frame: None,
             orbit,
             on_orbit: None,