diff --git a/crates/engine/src/cmd/draw2.rs b/crates/engine/src/cmd/draw2.rs
index 68dfd5db..388b8ba5 100644
--- a/crates/engine/src/cmd/draw2.rs
+++ b/crates/engine/src/cmd/draw2.rs
@@ -1083,7 +1083,9 @@ impl Interactive for RevcloudM {
         let first_kw: &[&str] = &["Arc length", "Object", "Rectangular", "Polygonal", "Freehand", "Style"];
         match (self.kind, self.pts.len()) {
             (CloudKind::Rect, 0) => Prompt::new("Specify first corner point", Accept::POINT).kw(first_kw).default("Object"),
-            (CloudKind::Rect, _) => Prompt::new("Specify opposite corner", Accept::POINT).base_opt(self.pts.first().copied()),
+            (CloudKind::Rect, _) => {
+                Prompt { corner: true, ..Prompt::new("Specify opposite corner", Accept::POINT).base_opt(self.pts.first().copied()) }
+            }
             (CloudKind::Poly, 0) => Prompt::new("Specify start point", Accept::POINT).kw(first_kw).default("Object"),
             (CloudKind::Poly, 1) => Prompt::new("Specify next point", Accept::POINT).base_opt(self.pts.last().copied()),
             (CloudKind::Poly, _) => Prompt::new("Specify next point", Accept::POINT).kw(&["Undo"]).base_opt(self.pts.last().copied()),
diff --git a/crates/engine/src/cmd/layout/viewports.rs b/crates/engine/src/cmd/layout/viewports.rs
index 7f47c4e3..e82d881f 100644
--- a/crates/engine/src/cmd/layout/viewports.rs
+++ b/crates/engine/src/cmd/layout/viewports.rs
@@ -637,13 +637,13 @@ impl Interactive for MviewM {
             Stage::Arrange => Prompt::new("Enter viewport arrangement", curves::KW)
                 .kw(&["Horizontal", "Vertical", "Above", "Below", "Left", "Right"])
                 .default("Right"),
-            Stage::Opposite(a) => Prompt::new("Specify opposite corner", Accept::POINT).base(*a),
+            Stage::Opposite(a) => Prompt::new("Specify opposite corner", Accept::POINT).corner(*a),
             Stage::Polygon(pi) => pi.prompt(),
             Stage::Object => Prompt::new("Select object to clip viewport", Accept::POINT),
             Stage::Lock => Prompt::new("Lock the view of viewports?", curves::KW).kw(&["ON", "OFF"]),
             Stage::RestoreName => Prompt::new("Enter viewport configuration name", Accept::TEXT).kw(&["?"]).default(VportConfig::ACTIVE),
             Stage::RestoreCorner(_) => Prompt::new("Specify first corner", Accept::POINT).kw(&["Fit"]).default("Fit"),
-            Stage::RestoreOpposite(_, a) => Prompt::new("Specify opposite corner", Accept::POINT).base(*a),
+            Stage::RestoreOpposite(_, a) => Prompt::new("Specify opposite corner", Accept::POINT).corner(*a),
             Stage::Select { .. } => Prompt::new("Select viewports", Accept::POINT),
         }
     }
diff --git a/crates/engine/src/cmd/modify.rs b/crates/engine/src/cmd/modify.rs
index 059beb6a..715ad895 100644
--- a/crates/engine/src/cmd/modify.rs
+++ b/crates/engine/src/cmd/modify.rs
@@ -517,7 +517,7 @@ impl Interactive for StretchM {
             return m.prompt();
         }
         match (self.phase, self.corner) {
-            (StretchPhase::Select, Some(c)) => Prompt::new("Specify opposite corner", Accept::POINT).base(c),
+            (StretchPhase::Select, Some(c)) => Prompt::new("Specify opposite corner", Accept::POINT).corner(c),
             (StretchPhase::Select, None) => Prompt::new(if self.removing { "Remove objects" } else { "Select objects" }, Accept::POINT),
             (StretchPhase::Base, _) => Prompt::new("Specify base point", Accept::POINT).kw(&["Displacement"]).default("Displacement"),
             (StretchPhase::Displacement, _) => Prompt::new("Specify displacement", Accept::POINT).default("0,0"),
diff --git a/crates/engine/src/cmd/plotters.rs b/crates/engine/src/cmd/plotters.rs
index 454b977a..762f6506 100644
--- a/crates/engine/src/cmd/plotters.rs
+++ b/crates/engine/src/cmd/plotters.rs
@@ -365,7 +365,7 @@ impl Interactive for PlotWindowM {
     fn prompt(&self, _s: &Session) -> Prompt {
         match self.first {
             None => Prompt::new("Specify first corner", Accept::POINT),
-            Some(a) => Prompt::new("Specify opposite corner", Accept::POINT).base(a),
+            Some(a) => Prompt::new("Specify opposite corner", Accept::POINT).corner(a),
         }
     }
     fn input(&mut self, s: &mut Session, i: Input) -> Result<Step> {
diff --git a/crates/engine/src/cmd/view/named_views.rs b/crates/engine/src/cmd/view/named_views.rs
index 40c25632..ef2750ef 100644
--- a/crates/engine/src/cmd/view/named_views.rs
+++ b/crates/engine/src/cmd/view/named_views.rs
@@ -279,7 +279,7 @@ impl Interactive for ViewM {
             Stage::Restore => Prompt::new("Enter view name to restore", Accept::TEXT),
             Stage::Save | Stage::WindowName => Prompt::new("Enter view name to save", Accept::TEXT),
             Stage::WindowFirst => Prompt::new("Specify first corner", Accept::POINT),
-            Stage::WindowSecond(a) => Prompt::new("Specify opposite corner", Accept::POINT).base(a),
+            Stage::WindowSecond(a) => Prompt::new("Specify opposite corner", Accept::POINT).corner(a),
             Stage::Settings => Prompt::new("Enter an option", Accept::TEXT).kw(&["Layer snapshot"]),
             Stage::Snapshot => {
                 let on = if s.settings.view_layer_snapshot { "Yes" } else { "No" };
diff --git a/crates/engine/src/select.rs b/crates/engine/src/select.rs
index 7666ab54..d3db01c9 100644
--- a/crates/engine/src/select.rs
+++ b/crates/engine/src/select.rs
@@ -434,7 +434,7 @@ impl SelectMode {
         };
         match last {
             None => Prompt::new(first, Accept::POINT),
-            Some(p) if self.is_box() => Prompt::new(next, Accept::POINT).base(p),
+            Some(p) if self.is_box() => Prompt::new(next, Accept::POINT).corner(p),
             Some(p) => Prompt::new(next, Accept::POINT).kw(&["Undo"]).base(p),
         }
     }
diff --git a/crates/engine/tests/stretch_window_ortho.rs b/crates/engine/tests/stretch_window_ortho.rs
new file mode 100644
index 00000000..70a7fdbf
--- /dev/null
+++ b/crates/engine/tests/stretch_window_ortho.rs
@@ -0,0 +1,79 @@
+//! STRETCH's crossing window ignores ortho: the opposite corner is where the cursor is, so the
+//! window keeps its area and catches what it crosses. The same holds for every rectangle picked by
+//! two corners (PLOTWINDOW, MVIEW, -VIEW Window, REVCLOUD Rectangular).
+
+use cadcraft_engine::snap::tracking::CursorQuery;
+use cadcraft_engine::{Input, Session};
+use cadcraft_geom::Vec2;
+use serde_json::json;
+
+/// Move the cursor to `raw` at the current prompt, as the canvas does.
+fn hover(s: &mut Session, raw: Vec2) -> Vec2 {
+    let p = s.current_prompt().unwrap();
+    let q = CursorQuery { base: p.base, deferred: p.deferred, corner: p.corner, aperture: 1e-6, tol: 1e-6, now: 0.0, shift: false };
+    let c = s.snap_cursor(raw, &q).point;
+    s.cursor = c;
+    c
+}
+
+/// A session with ortho on, object snaps off and a line from 0,0 to 10,0.
+fn ortho_session() -> Session {
+    let mut s = Session::new();
+    s.execute("setvar", &json!({ "name": "OSMODE", "value": 0 })).unwrap();
+    s.execute("setvar", &json!({ "name": "ORTHOMODE", "value": 1 })).unwrap();
+    s.execute("line", &json!({ "points": [[0, 0], [10, 0]] })).unwrap();
+    s
+}
+
+/// Pick the window's opposite corner at `to`, stretch by 5,0 and return the extents.
+fn stretch_from_corner(mut s: Session, to: Vec2) -> (Vec2, Vec2) {
+    assert_eq!(s.current_prompt().unwrap().message, "Specify opposite corner");
+    let c = hover(&mut s, to);
+    assert!(c.near(to, 1e-9), "the corner is where the cursor is: {c:?}");
+    s.input(Input::Point(c)).unwrap();
+    s.input(Input::Enter).unwrap();
+    for t in ["0,0", "5,0"] {
+        s.cmdline(t).unwrap();
+    }
+    assert!(s.current_prompt().is_none(), "STRETCH is done, still at {:?}", s.current_prompt().map(|p| p.message));
+    let b = s.doc().unwrap().extents(&s.space());
+    (b.min, b.max)
+}
+
+#[test]
+fn stretch_implied_window_ignores_ortho() {
+    let mut s = ortho_session();
+    s.cmdline("stretch").unwrap();
+    // Right to left: a crossing window.
+    s.input(Input::Point(Vec2::new(12.0, 1.0))).unwrap();
+    assert_eq!(stretch_from_corner(s, Vec2::new(8.0, -1.0)), (Vec2::ZERO, Vec2::new(15.0, 0.0)), "the line's end moved by 5");
+}
+
+#[test]
+fn stretch_crossing_mode_ignores_ortho() {
+    let mut s = ortho_session();
+    for t in ["stretch", "c", "8,-1"] {
+        s.cmdline(t).unwrap();
+    }
+    assert_eq!(stretch_from_corner(s, Vec2::new(12.0, 1.0)), (Vec2::ZERO, Vec2::new(15.0, 0.0)), "the line's end moved by 5");
+}
+
+#[test]
+fn rectangle_corner_prompts_ignore_ortho() {
+    for script in [&["plotwindow", "0,0"][..], &["mview", "0,0"], &["-view", "w", "v1", "0,0"], &["revcloud", "r", "0,0"]] {
+        let mut s = Session::new();
+        s.execute("setvar", &json!({ "name": "OSMODE", "value": 0 })).unwrap();
+        s.execute("setvar", &json!({ "name": "ORTHOMODE", "value": 1 })).unwrap();
+        if script[0] == "mview" {
+            s.cmdline("layout s Layout1").unwrap();
+        }
+        for t in script {
+            s.cmdline(t).unwrap();
+        }
+        let p = s.current_prompt().unwrap();
+        assert_eq!(p.message, "Specify opposite corner", "{script:?}");
+        assert!(p.corner, "{script:?}: the opposite corner ignores ortho");
+        let c = hover(&mut s, Vec2::new(10.0, 4.0));
+        assert!(c.near(Vec2::new(10.0, 4.0), 1e-9), "{script:?}: the corner is where the cursor is: {c:?}");
+    }
+}