diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index 5c4b70df..ad94b596 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -183,6 +183,7 @@ pub fn show(app: &mut FigApp, ui: &mut Ui, worker: &mut Worker) {
         }
     }
     let own_cursor = input(app, ui, &resp);
+    crate::guides::end_released(&ctx);
     crate::live::track_pointer(app, &ctx);
     app.sync_preedit();
     request_render(app, worker, ppp);
diff --git a/crates/ui-egui/src/guide_release_tests.rs b/crates/ui-egui/src/guide_release_tests.rs
new file mode 100644
index 00000000..b2e0f015
--- /dev/null
+++ b/crates/ui-egui/src/guide_release_tests.rs
@@ -0,0 +1,85 @@
+//! Ruler guide drags released off the canvas, driven through egui headless: the gesture ends there,
+//! and a later click on the canvas neither adds a guide nor moves one.
+
+use egui::{Event, Pos2, vec2};
+use figcraft_engine::Session;
+use serde_json::json;
+
+use crate::layers_drag_tests::Ui;
+
+fn rulers() -> Ui {
+    let mut s = Session::new();
+    s.execute("view.rulers", &json!({"on": true})).unwrap();
+    Ui::new(s)
+}
+
+fn offsets(u: &Ui) -> Vec<f64> {
+    let ds = u.app.session.ds().unwrap();
+    ds.doc.node(ds.page).unwrap().guides().iter().map(|g| g.offset).collect()
+}
+
+fn drag(u: &mut Ui, from: Pos2, to: Pos2) {
+    u.frame(vec![Event::PointerMoved(from)]);
+    u.button(from, true);
+    u.frame(vec![Event::PointerMoved(to)]);
+    u.button(to, false);
+}
+
+fn click(u: &mut Ui, p: Pos2) {
+    u.frame(vec![Event::PointerMoved(p)]);
+    u.button(p, true);
+    u.button(p, false);
+}
+
+#[test]
+fn a_ruler_drag_released_off_the_canvas_adds_no_guide_on_a_later_click() {
+    for left in [false, true] {
+        let mut u = rulers();
+        let r = u.app.canvas.rect;
+        let start = if left { Pos2::new(r.min.x + 5.0, r.min.y + 60.0) } else { Pos2::new(r.min.x + 60.0, r.min.y + 5.0) };
+        drag(&mut u, start, Pos2::new(r.min.x - 100.0, r.center().y));
+        let released = offsets(&u);
+        click(&mut u, r.center() + vec2(30.0, 60.0));
+        assert_eq!(offsets(&u), released, "left ruler: {left}");
+    }
+}
+
+#[test]
+fn a_ruler_drag_released_off_the_canvas_ends_even_when_the_next_frame_presses() {
+    let mut u = rulers();
+    let r = u.app.canvas.rect;
+    let start = Pos2::new(r.min.x + 60.0, r.min.y + 5.0);
+    let off = Pos2::new(r.min.x - 100.0, r.center().y);
+    u.frame(vec![Event::PointerMoved(start)]);
+    u.button(start, true);
+    u.frame(vec![Event::PointerMoved(off)]);
+    u.button(off, false);
+    let p = r.center() + vec2(30.0, 60.0);
+    u.button(p, true);
+    u.button(p, false);
+    assert!(offsets(&u).is_empty());
+}
+
+#[test]
+fn a_guide_moved_off_the_canvas_doesnt_follow_a_later_click() {
+    let mut u = rulers();
+    let r = u.app.canvas.rect;
+    drag(&mut u, Pos2::new(r.min.x + 60.0, r.min.y + 5.0), r.center());
+    assert_eq!(offsets(&u).len(), 1);
+    drag(&mut u, r.center(), Pos2::new(r.min.x - 100.0, r.center().y));
+    let released = offsets(&u);
+    click(&mut u, r.center() + vec2(30.0, 60.0));
+    assert_eq!(offsets(&u), released);
+}
+
+#[test]
+fn a_ruler_drag_released_on_the_canvas_adds_one_guide() {
+    let mut u = rulers();
+    let r = u.app.canvas.rect;
+    drag(&mut u, Pos2::new(r.min.x + 60.0, r.min.y + 5.0), r.center());
+    assert_eq!(offsets(&u).len(), 1);
+    click(&mut u, r.center() + vec2(30.0, 60.0));
+    assert_eq!(offsets(&u).len(), 1);
+    u.app.session.execute("edit.undo", &json!({})).unwrap();
+    assert!(offsets(&u).is_empty());
+}
diff --git a/crates/ui-egui/src/guides.rs b/crates/ui-egui/src/guides.rs
index b4a7cc0d..69ab8ee8 100644
--- a/crates/ui-egui/src/guides.rs
+++ b/crates/ui-egui/src/guides.rs
@@ -279,6 +279,19 @@ pub fn input(app: &mut FigApp, ctx: &egui::Context, pos: Pos2) -> bool {
     false
 }
 
+/// Ends a guide drag whose button is up by the end of the frame without [`input`] taking the
+/// release (released off the canvas, or over something on it): the gesture is dropped, so a later
+/// click doesn't add or move a guide.
+pub fn end_released(ctx: &egui::Context) {
+    if ctx.input(|i| i.pointer.primary_down()) {
+        return;
+    }
+    ctx.data_mut(|d| {
+        d.remove::<GuideDrag>(drag_id());
+        d.remove::<Placed>(preview_id());
+    });
+}
+
 /// Draw the page's and its frames' guides (under the rulers) and the one being dragged with its
 /// position.
 pub fn draw(app: &FigApp, painter: &egui::Painter) {
diff --git a/crates/ui-egui/src/lib.rs b/crates/ui-egui/src/lib.rs
index 40f2d5b3..b727caa1 100644
--- a/crates/ui-egui/src/lib.rs
+++ b/crates/ui-egui/src/lib.rs
@@ -95,6 +95,8 @@ mod gap_handle_tests;
 #[cfg(test)]
 mod gradient_shorthand_tests;
 #[cfg(test)]
+mod guide_release_tests;
+#[cfg(test)]
 mod home_recents_tests;
 #[cfg(test)]
 mod home_tests;