diff --git a/crates/engine/src/cmd/organize.rs b/crates/engine/src/cmd/organize.rs
index 24cc2061c..50807e7cf 100644
--- a/crates/engine/src/cmd/organize.rs
+++ b/crates/engine/src/cmd/organize.rs
@@ -188,12 +188,27 @@ pub fn specs() -> Vec<CommandSpec> {
                 Ok(json!({"changed": commit_ops(s, "Split Stack", vec![op])?}))
             }
         ),
-        cmd!("stack.toggle", "Expand/Collapse Stack", ["Photo", "Stack"], Some("S"), "{ids?, collapsed?: bool}", in_stack, |s, p| {
-            let stacks = stacks_of(s, &s.targets(p)?);
-            let first = stacks.first().and_then(|id| s.catalog.stack(*id)).map(|st| st.collapsed).unwrap_or(false);
-            let collapsed = bool_or(p, "collapsed", !first);
-            set_collapsed(s, stacks, collapsed, if collapsed { "Collapse Stack" } else { "Expand Stack" })
-        }),
+        // `ids` names the stacks' photos without selecting them (a click on a stack badge)
+        CommandSpec {
+            explicit_targets: true,
+            ..cmd!(
+                "stack.toggle",
+                "Expand/Collapse Stack",
+                ["Photo", "Stack"],
+                Some("S"),
+                "{ids?, collapsed?: bool} — the stacks of the named photos (else of the selection)",
+                in_stack,
+                |s, p| {
+                    let stacks = stacks_of(s, &s.targets(p)?);
+                    if stacks.is_empty() {
+                        return Err(bad("stack.toggle", "none of the photos is in a stack"));
+                    }
+                    let first = stacks.first().and_then(|id| s.catalog.stack(*id)).map(|st| st.collapsed).unwrap_or(false);
+                    let collapsed = bool_or(p, "collapsed", !first);
+                    set_collapsed(s, stacks, collapsed, if collapsed { "Collapse Stack" } else { "Expand Stack" })
+                }
+            )
+        },
         cmd!("stack.expandAll", "Expand All Stacks", ["View", "Stacks"], None, "{}", has_stacks, |s, _| {
             let all: Vec<StackId> = s.catalog.stacks().map(|st| st.id).collect();
             set_collapsed(s, all, false, "Expand All Stacks")
diff --git a/crates/engine/src/tests_organize.rs b/crates/engine/src/tests_organize.rs
index 344838432..ea0414256 100644
--- a/crates/engine/src/tests_organize.rs
+++ b/crates/engine/src/tests_organize.rs
@@ -356,3 +356,27 @@ fn rename_huge_start_is_a_bad_param() {
     let r = s.execute("photo.renamePreview", &json!({"template": "{seq}", "start": fits + 1, "ids": ids}));
     assert!(r.is_err(), "{r:?}");
 }
+
+#[test]
+fn stack_toggle_by_ids_leaves_the_selection_alone() {
+    let mut s = Session::with_demo();
+    let vis = s.visible_cloned();
+    let (loose, top, member) = (vis[0], vis[1], vis[2]);
+    s.execute("library.select", &json!({"ids": [top.0, member.0], "active": top.0})).unwrap();
+    s.execute("stack.group", &json!({})).unwrap();
+    // a loose photo is selected: the stack is named by `ids` (a badge click), not selected
+    s.execute("library.select", &json!({"ids": [loose.0]})).unwrap();
+    let r = s.execute("stack.toggle", &json!({"ids": [member.0]})).unwrap();
+    assert_eq!(r["changed"], 1, "{r}");
+    assert!(!s.catalog.stack_of(top).unwrap().collapsed);
+    assert_eq!((s.selection.ids.clone(), s.selection.active), (vec![loose], Some(loose)), "the selection is untouched");
+    s.execute("stack.toggle", &json!({"ids": [top.0]})).unwrap();
+    assert!(s.catalog.stack_of(top).unwrap().collapsed);
+    // naming only loose photos is refused without a commit, as is an unknown id
+    let commits = s.commits();
+    assert!(s.execute("stack.toggle", &json!({"ids": [loose.0]})).is_err());
+    assert!(s.execute("stack.toggle", &json!({"ids": [999_999]})).is_err());
+    assert_eq!(s.commits(), commits);
+    // without `ids` the selection still decides (a loose photo selected: not available)
+    assert!(matches!(s.execute("stack.toggle", &json!({})), Err(crate::EngineError::Disabled(..))));
+}
diff --git a/crates/ui-egui/src/panels/detail.rs b/crates/ui-egui/src/panels/detail.rs
index 07e1ca7f6..22891a10d 100644
--- a/crates/ui-egui/src/panels/detail.rs
+++ b/crates/ui-egui/src/panels/detail.rs
@@ -2654,6 +2654,7 @@ pub(crate) fn filmstrip(app: &mut LightcraftApp, ui: &mut egui::Ui, r: Rect) {
                     } else {
                         "Stack — click to collapse"
                     });
+                    crate::widgets::announce(&badge, crate::i18n::tr(if collapsed { "Expand Stack" } else { "Collapse Stack" }));
                     register(ui.ctx(), format!("filmstack:{}", id.0), br);
                     let p = ui.painter();
                     let fill = if badge.hovered() { Color32::from_black_alpha(230) } else { Color32::from_black_alpha(170) };
diff --git a/crates/ui-egui/src/panels/grid.rs b/crates/ui-egui/src/panels/grid.rs
index aec87d3a9..f527eacb5 100644
--- a/crates/ui-egui/src/panels/grid.rs
+++ b/crates/ui-egui/src/panels/grid.rs
@@ -1026,6 +1026,7 @@ pub fn stack_badge(app: &mut LightcraftApp, ui: &mut egui::Ui, id: PhotoId, sid:
     } else {
         "Stack — click to collapse (S)"
     });
+    crate::widgets::announce(&resp, crate::i18n::tr(if collapsed { "Expand Stack" } else { "Collapse Stack" }));
     register(ui.ctx(), format!("stack:{}", id.0), br);
     let fill = if resp.hovered() { Color32::from_black_alpha(220) } else { Color32::from_black_alpha(165) };
     p.rect_filled(br, 10.0, fill);
@@ -1039,12 +1040,9 @@ pub fn stack_badge(app: &mut LightcraftApp, ui: &mut egui::Ui, id: PhotoId, sid:
     }
 }
 
-/// A click on a stack badge (grid or filmstrip): expand / collapse that photo's stack. The
-/// photo is selected first when it isn't, as `stack.toggle` acts on a selected stack.
+/// A click on a stack badge (grid or filmstrip): expand / collapse that photo's stack, selected or
+/// not. The selection stays as it is (Compare keeps its pair).
 pub fn toggle_stack(app: &mut LightcraftApp, ctx: &egui::Context, id: PhotoId) {
-    if !app.session.selection.contains(id) {
-        let _ = app.run("library.select", json!({"ids": [id.0]}));
-    }
     if let Err(e) = app.run("stack.toggle", json!({"ids": [id.0]})) {
         app.toast(ctx, e);
     }
diff --git a/crates/ui-egui/src/tests_filmstrip.rs b/crates/ui-egui/src/tests_filmstrip.rs
index 6aedb93ac..bf572c1d6 100644
--- a/crates/ui-egui/src/tests_filmstrip.rs
+++ b/crates/ui-egui/src/tests_filmstrip.rs
@@ -51,6 +51,7 @@ fn filmstrip_stack_badge_expands_and_collapses_the_stack() {
     h.settle(SETTLE);
     assert!(!h.app.session.catalog.stack(StackId(1)).unwrap().collapsed, "a click on the badge expands the stack");
     assert!(h.app.session.visible_cloned().contains(&member));
+    assert_eq!(h.app.session.selection.active, Some(loose), "the loupe keeps its photo");
     let r = h.request("ui.clickWidget", json!({"id": badge}), T);
     assert_eq!(r["ok"], true, "{r}");
     h.settle(SETTLE);
diff --git a/crates/ui-egui/src/tests_grid.rs b/crates/ui-egui/src/tests_grid.rs
index 713db7ecf..1506ff06e 100644
--- a/crates/ui-egui/src/tests_grid.rs
+++ b/crates/ui-egui/src/tests_grid.rs
@@ -189,4 +189,5 @@ fn grid_stack_badge_toggles_a_stack_that_is_not_selected() {
     assert_eq!(r["ok"], true, "{r}");
     h.settle(SETTLE);
     assert!(h.app.session.catalog.stack_of(top).unwrap().collapsed, "a click on an unselected stack's badge toggles it");
+    assert_eq!((h.app.session.selection.ids.clone(), h.app.session.selection.active), (vec![loose], Some(loose)), "and leaves the selection alone");
 }