diff --git a/crates/ui-egui/src/dialogs/live_shape_prompt.rs b/crates/ui-egui/src/dialogs/live_shape_prompt.rs
index b963516bc4..6db96b6760 100644
--- a/crates/ui-egui/src/dialogs/live_shape_prompt.rs
+++ b/crates/ui-egui/src/dialogs/live_shape_prompt.rs
@@ -32,7 +32,7 @@ fn is_live(app: &PhotocraftApp, r: PathRef) -> bool {
 /// or "Don't show again" was ticked.
 pub fn ask(app: &mut PhotocraftApp, r: PathRef, params: &Value) -> bool {
     let PathRef::Layer(layer) = r else { return false };
-    let Some(document) = app.session.active().map(|st| st.doc.id.0) else { return false };
+    let Some((document, revision)) = app.session.active().map(|st| (st.doc.id.0, st.revision)) else { return false };
     if !is_live(app, r) || dont_show_again::dismissed(app, PREF) {
         return false;
     }
@@ -44,8 +44,10 @@ pub fn ask(app: &mut PhotocraftApp, r: PathRef, params: &Value) -> bool {
     f.insert("__command".into(), json!("path.deleteAnchor"));
     f.insert("__label".into(), json!(tl!("Delete Anchor Point")));
     f.insert("layer".into(), json!(layer));
-    // The layer id means something only in this document (another may become active meanwhile).
+    // The layer id means something only in this document (another may become active meanwhile),
+    // and the knot index only in this revision of it (an edit meanwhile can shift the anchors).
     f.insert("__document".into(), json!(document));
+    f.insert("__revision".into(), json!(revision));
     f.insert("params".into(), params.clone());
     f.insert("__dontShowAgain".into(), json!(PREF));
     f.insert("skip".into(), json!(false));
@@ -62,8 +64,8 @@ pub fn body(ui: &mut egui::Ui, fields: &mut Map<String, Value>) {
 pub fn confirm(app: &mut PhotocraftApp, fields: &Map<String, Value>) -> Result<Value, String> {
     let layer = fields.get("layer").and_then(Value::as_u64).ok_or(tl!("No anchor to delete"))?;
     let params = fields.get("params").cloned().ok_or(tl!("No anchor to delete"))?;
-    let document = fields.get("__document").and_then(Value::as_u64);
-    if document.is_none() || app.session.active().map(|st| st.doc.id.0) != document {
+    let asked = fields.get("__document").and_then(Value::as_u64).zip(fields.get("__revision").and_then(Value::as_u64));
+    if asked.is_none() || app.session.active().map(|st| (st.doc.id.0, st.revision)) != asked {
         return Err(tl!("No anchor to delete").into());
     }
     let result = app.run("path.deleteAnchor", params)?;
diff --git a/crates/ui-egui/src/tools/anchor_tools/delete_anchor_live_shape_tests.rs b/crates/ui-egui/src/tools/anchor_tools/delete_anchor_live_shape_tests.rs
index 015a4a7e04..fdccea07e0 100644
--- a/crates/ui-egui/src/tools/anchor_tools/delete_anchor_live_shape_tests.rs
+++ b/crates/ui-egui/src/tools/anchor_tools/delete_anchor_live_shape_tests.rs
@@ -104,6 +104,20 @@ fn yes_after_another_document_became_active_deletes_nothing() {
     assert_eq!(corners(&mut app, shape), 4, "the first document's shape keeps its corner");
 }
 
+/// The question's knot index belongs to the path as it was asked: an anchor added before the
+/// corner meanwhile (through the control channel; the question is modal on screen) shifts it, so Yes
+/// is refused instead of deleting another anchor.
+#[test]
+fn yes_after_the_path_changed_deletes_nothing() {
+    let (mut app, shape) = live(Tool::DeleteAnchorPoint);
+    click(&mut app, CORNER);
+    let id = question(&app).expect("the question");
+    app.run("path.addAnchor", json!({"name": "layer", "layer": shape, "subpath": 0, "knot": 0, "t": 0.5})).unwrap();
+    let (before, n) = (shape_path(&mut app, shape), steps(&app));
+    assert!(crate::dialogs::confirm(&mut app, id).is_err());
+    assert_eq!((shape_path(&mut app, shape), steps(&app)), (before, n));
+}
+
 #[test]
 fn no_leaves_the_shape_its_parameters_and_history_unchanged() {
     let (mut app, shape) = live(Tool::DeleteAnchorPoint);