diff --git a/crates/engine/src/cmd/key_transform.rs b/crates/engine/src/cmd/key_transform.rs
index b78439266..641759095 100644
--- a/crates/engine/src/cmd/key_transform.rs
+++ b/crates/engine/src/cmd/key_transform.rs
@@ -72,6 +72,10 @@ fn transform(s: &mut Session, p: &Value) -> Result<Value> {
         let mut new_sel = vec![];
         for ((lid, uid), times) in groups {
             let Some(layer) = comp.layer_mut(lid) else { continue };
+            if layer.switches.locked {
+                new_sel.extend(times.into_iter().map(|time| KeyRef { layer: lid, prop: uid, time }));
+                continue;
+            }
             let (start, stretch) = (layer.start_time, layer.stretch);
             let to_comp = |lt: Tick| if (stretch - 100.0).abs() < 1e-9 { start + lt } else { start + Tick((lt.0 as f64 * stretch / 100.0) as i64) };
             let to_layer = |ct: Tick| {
diff --git a/crates/engine/src/tests/delete_keys.rs b/crates/engine/src/tests/delete_keys.rs
index 829331fd7..fb8162855 100644
--- a/crates/engine/src/tests/delete_keys.rs
+++ b/crates/engine/src/tests/delete_keys.rs
@@ -84,3 +84,42 @@ fn selection_based_key_edits_skip_a_locked_layer() {
     s.execute_checked("keys.easyEase", json!({})).unwrap();
     assert_ne!(stored(&s), before, "unlocked, Easy Ease changes the keys");
 }
+
+#[test]
+fn key_transform_preserves_locked_keys_in_a_mixed_selection() {
+    let (mut s, locked, locked_prop) = setup();
+    let unlocked = s.execute("layer.newSolid", json!({"name": "Unlocked", "color": "#fff"})).unwrap()["layer"].as_u64().unwrap();
+    for t in 0..3 {
+        s.execute("prop.addKey", json!({"layer": unlocked, "path": "transform/opacity", "time": t, "value": t * 25})).unwrap();
+    }
+    let unlocked_prop = s.active_comp().unwrap().layer(LayerId(unlocked)).unwrap().props.prop("transform/opacity").unwrap().uid;
+    let locked_keys = keys_of(&s, locked, locked_prop);
+    s.state.selected_keys = locked_keys.iter().chain(keys_of(&s, unlocked, unlocked_prop).iter()).copied().collect();
+    s.execute("layer.setSwitch", json!({"layers": [locked], "switch": "locked", "value": true})).unwrap();
+    let stored = |s: &Session, layer, prop| s.active_comp().unwrap().layer(LayerId(layer)).unwrap().props.find(prop).unwrap().keys.clone();
+    let before = stored(&s, locked, locked_prop);
+    let undo = s.history.undo.len();
+    for offset in [0.5, 1.0] {
+        s.execute("keys.transform", json!({"timeOffset": offset, "valueOffset": offset * 10.0, "merge": "mixed-transform", "fromStart": true})).unwrap();
+        assert_eq!(stored(&s, locked, locked_prop), before);
+        assert_eq!(s.state.selected_keys.len(), 6);
+        assert!(locked_keys.iter().all(|k| s.state.selected_keys.contains(k)), "locked selections stay at their original times");
+        assert!(keys_of(&s, unlocked, unlocked_prop).iter().all(|k| s.state.selected_keys.contains(k)), "unlocked selections follow the keys");
+        let moved = stored(&s, unlocked, unlocked_prop);
+        for (i, key) in moved.iter().enumerate() {
+            assert_eq!(key.time.seconds(), i as f64 + offset);
+            assert_eq!(key.value.as_f64(), i as f64 * 25.0 + offset * 10.0);
+        }
+    }
+    assert_eq!(s.history.undo.len(), undo + 1, "one merged drag");
+    let after = stored(&s, unlocked, unlocked_prop);
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(stored(&s, locked, locked_prop), before);
+    assert_eq!(stored(&s, unlocked, unlocked_prop), before);
+    s.execute("edit.redo", json!({})).unwrap();
+    assert_eq!(stored(&s, locked, locked_prop), before);
+    assert_eq!(stored(&s, unlocked, unlocked_prop), after);
+    s.execute("layer.setSwitch", json!({"layers": [locked], "switch": "locked", "value": false})).unwrap();
+    s.execute("keys.transform", json!({"timeOffset": 0.5, "valueOffset": 10})).unwrap();
+    assert_ne!(stored(&s, locked, locked_prop), before, "unlocking makes the keys editable again");
+}
diff --git a/crates/ui-egui/src/panels/timeline/tests.rs b/crates/ui-egui/src/panels/timeline/tests.rs
index ee0e39ca3..4b7bdefd5 100644
--- a/crates/ui-egui/src/panels/timeline/tests.rs
+++ b/crates/ui-egui/src/panels/timeline/tests.rs
@@ -552,29 +552,34 @@ fn the_key_menu_is_translated_and_cannot_edit_a_locked_layers_keys() {
     let layer = app.session.active_comp().unwrap().layer(LayerId(id)).unwrap().clone();
     let prop = layer.props.prop("transform/opacity").unwrap().clone();
     let key = prop.keys[0].clone();
-    let enabled = |locked: bool, label: &str| {
+    let enabled = |locked: bool, selected: bool, label: &str| {
         let mut layer = layer.clone();
         layer.switches.locked = locked;
         let mut actions = vec![];
-        let mut h = Harness::new_ui(|ui| key_menu(ui, &app, &layer, &prop, &key, true, &mut actions));
+        let mut h = Harness::new_ui(|ui| key_menu(ui, &app, &layer, &prop, &key, selected, &mut actions));
         h.run();
         !h.get_by_label(label).accesskit_node().is_disabled()
     };
     for label in
         ["Copy", "Select Equal Keyframes", "Select All Keyframes", "Delete", "Edit Value…", "Easy Ease", "Time-Reverse Keyframes", "Keyframe Velocity…"]
     {
-        assert!(enabled(false, label), "{label} on an unlocked layer");
+        assert!(enabled(false, true, label), "{label} on an unlocked layer");
     }
     for label in ["Copy", "Select Equal Keyframes", "Select All Keyframes"] {
-        assert!(enabled(true, label), "{label} is still available on a locked layer");
+        assert!(enabled(true, true, label), "{label} is still available on a locked layer");
     }
     for label in ["Delete", "Edit Value…", "Easy Ease", "Time-Reverse Keyframes", "Keyframe Velocity…", "Linear"] {
-        assert!(!enabled(true, label), "{label} is off on a locked layer");
+        assert!(!enabled(true, true, label), "{label} is off on a locked layer");
+        assert!(!enabled(true, false, label), "{label} is off on an unselected locked key");
     }
+    for label in ["Copy", "Select Equal Keyframes", "Select Previous Keyframes", "Select Following Keyframes"] {
+        assert!(!enabled(true, false, label), "{label} requires selecting the clicked key");
+    }
+    assert!(enabled(true, false, "Select All Keyframes"));
     // The labels follow the interface language.
     crate::i18n::set_current("es");
     let copy = crate::i18n::context_item("keys.copy", &json!({}), "Copy");
     assert_ne!(copy, "Copy", "the catalog translates Copy");
-    assert!(enabled(false, &copy));
+    assert!(enabled(false, true, &copy));
     crate::i18n::set_current("en");
 }