diff --git a/crates/ui-egui/src/panels/rules_editor.rs b/crates/ui-egui/src/panels/rules_editor.rs
index 1ee1872db..b85d7b3be 100644
--- a/crates/ui-egui/src/panels/rules_editor.rs
+++ b/crates/ui-egui/src/panels/rules_editor.rs
@@ -131,13 +131,17 @@ fn value_editor(ui: &mut egui::Ui, field: &str, op: &str, v: &mut Value, salt: &
             );
         }
         (Some(Kind::Bool), _) => {
-            // the catalog's reading of the value ("false" is no), stored back as a plain boolean
-            let mut b = bool_value(v).unwrap_or(true);
-            egui::ComboBox::from_id_salt(format!("{salt}-bool")).width(60.0).selected_text(crate::i18n::bool_text(b)).show_ui(ui, |ui| {
-                ui.selectable_value(&mut b, true, crate::i18n::bool_text(true));
-                ui.selectable_value(&mut b, false, crate::i18n::bool_text(false));
+            // the catalog's reading of the value ("false" is no); one that is neither yes nor no is
+            // shown as written and kept until a choice replaces it, so the dialog reports it
+            let cur = bool_value(v);
+            let text = cur.map_or_else(|| v.to_string(), |b| crate::i18n::bool_text(b).to_string());
+            egui::ComboBox::from_id_salt(format!("{salt}-bool")).width(60.0).selected_text(text).show_ui(ui, |ui| {
+                for b in [true, false] {
+                    if ui.selectable_label(cur == Some(b), crate::i18n::bool_text(b)).clicked() {
+                        *v = json!(b);
+                    }
+                }
             });
-            *v = json!(b);
         }
         (Some(Kind::Date), _) => text_value(ui, v, 120.0, "2026-04 or 2026-04-12", salt),
         _ => text_value(ui, v, 140.0, "", salt),
diff --git a/crates/ui-egui/src/tests_masking.rs b/crates/ui-egui/src/tests_masking.rs
index cbafe8f1e..fd64b0a94 100644
--- a/crates/ui-egui/src/tests_masking.rs
+++ b/crates/ui-egui/src/tests_masking.rs
@@ -324,6 +324,22 @@ fn smart_album_field_menu_groups_fields_in_submenus() {
     assert!(!has(&h, "ruleFieldItem:rating:rules-0") && !has(&h, "ruleFieldItem:filePath:rules-0"), "picking a field closes the menu");
 }
 
+/// A yes/no rule whose value isn't yes or no (written by an agent or an older version) stays as
+/// it is in the editor: the dialog shows the problem and OK doesn't quietly save it as Yes.
+#[test]
+fn smart_album_editor_keeps_an_unreadable_yes_no_value() {
+    let mut h = detail("panel.edit");
+    exec(&mut h, "dialog.smartAlbum", json!({"name": "Odd"}));
+    let Some(crate::state::Dialog::SmartRules { rules, .. }) = &mut h.app.ui.dialog else { panic!("no rule editor") };
+    rules.rules[0] = serde_json::from_value(json!({"field": "edited", "op": "is", "value": "maybe"})).unwrap();
+    h.settle(SETTLE);
+    let Some(crate::state::Dialog::SmartRules { rules, .. }) = &h.app.ui.dialog else { panic!("no rule editor") };
+    let Rule::Field { value, .. } = &rules.rules[0] else { panic!("not a field rule") };
+    assert_eq!(value, &json!("maybe"), "drawing the editor doesn't rewrite the value");
+    let r = h.request("ui.dialog.confirm", json!({}), T);
+    assert!(h.app.session.catalog.albums().all(|a| a.name != "Odd"), "OK refuses it: {r}");
+}
+
 #[test]
 fn g_toggles_grids_and_shift_g_starts_guided_upright() {
     let mut h = detail("panel.edit");