diff --git a/crates/engine/src/cmd/mod.rs b/crates/engine/src/cmd/mod.rs
index 8e348b8f..5fb39922 100644
--- a/crates/engine/src/cmd/mod.rs
+++ b/crates/engine/src/cmd/mod.rs
@@ -493,6 +493,9 @@ pub use flatten::FlattenOptions;
 /// A built-in or saved flattener preset ([`crate::Prefs::flattener_presets`]).
 pub use flatten::FlattenerPreset;
 
+/// The shapes a group selected alone gives the Pathfinder panel.
+pub use pathops::shape_count;
+
 /// Command ids kept only so older scripts keep working: `(alias, the command it duplicates)`.
 /// They run as before but the command palette leaves them out (it lists the command once).
 pub const ALIASES: &[(&str, &str)] = &[("object.convertDocumentColorMode", "file.documentColorMode")];
diff --git a/crates/engine/src/cmd/pathops.rs b/crates/engine/src/cmd/pathops.rs
index fe33554f..b3354b08 100644
--- a/crates/engine/src/cmd/pathops.rs
+++ b/crates/engine/src/cmd/pathops.rs
@@ -258,6 +258,14 @@ fn leaves(n: &Node, out: &mut Vec<Node>) {
     }
 }
 
+/// How many shapes a Pathfinder operation takes from `n` selected alone: its leaf shapes, however
+/// deep its groups nest (an expanded stroke is a group inside the group, #1635).
+pub fn shape_count(n: &Node) -> usize {
+    let mut lv = vec![];
+    leaves(n, &mut lv);
+    lv.len()
+}
+
 /// A node for `path`: a plain path for one subpath, else a compound path.
 pub(crate) fn shape_node(d: &mut Document, path: PathData, style_src: Option<&Node>) -> Node {
     let id = d.alloc_id();
diff --git a/crates/ui-egui/src/panels/pathfinder.rs b/crates/ui-egui/src/panels/pathfinder.rs
index 6a78816f..42577236 100644
--- a/crates/ui-egui/src/panels/pathfinder.rs
+++ b/crates/ui-egui/src/panels/pathfinder.rs
@@ -29,12 +29,12 @@ fn run(app: &mut VectorcraftApp, ui: &Ui, op: &str, label: &str) {
     }
 }
 
-/// How many objects the selection gives an operation: a group selected alone counts as its
-/// members (#1450).
+/// How many objects the selection gives an operation: a group selected alone counts as the shapes
+/// the operation takes from it, nested groups included (#1450, #1635).
 fn operands(app: &VectorcraftApp) -> usize {
     let alone = app.session.active().filter(|d| d.selection.len() == 1).and_then(|d| d.doc.node(*d.selection.objects.first()?));
-    match alone.and_then(|n| n.children().filter(|_| matches!(n.kind, vectorcraft_doc::NodeKind::Group { .. }))) {
-        Some(members) => members.len(),
+    match alone.filter(|n| matches!(n.kind, vectorcraft_doc::NodeKind::Group { .. })) {
+        Some(group) => vectorcraft_engine::cmd::shape_count(group),
         None => selection_len(app),
     }
 }
@@ -96,3 +96,33 @@ pub fn menu(app: &mut VectorcraftApp, ui: &mut Ui) {
     menu_item(ui, tl!("Release Compound Shape"), false, false);
     menu_item(ui, tl!("Expand Compound Shape"), false, false);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use vectorcraft_engine::doc::{NodeId, NodeKind};
+
+    /// #1635: a stroked object expanded inside a group leaves a group holding one group (its fill
+    /// and its outlined stroke). The Shape Modes take the group's shapes, so they stay enabled, and
+    /// Unite merges the fill and the stroke into one path.
+    #[test]
+    fn shape_modes_take_the_shapes_of_an_expanded_stroke_in_a_group() {
+        let mut app = VectorcraftApp::new(vectorcraft_engine::Session::new(), Default::default());
+        app.run("file.new", json!({"width": 200, "height": 200})).unwrap();
+        app.run("shape.rectangle", json!({"x": 10, "y": 10, "width": 50, "height": 50})).unwrap();
+        app.run("stroke.set", json!({"weight": 10})).unwrap();
+        app.run("object.group", json!({})).unwrap();
+        app.run("object.expand", json!({})).unwrap();
+        let doc = &app.session.active().unwrap().doc;
+        let group = doc.node(*app.session.active().unwrap().selection.objects.first().unwrap()).unwrap();
+        let members = group.children().unwrap();
+        assert_eq!(members.len(), 1, "one member: the expanded rectangle");
+        assert!(matches!(members[0].kind, NodeKind::Group { .. }), "the fill and the outlined stroke, grouped");
+        assert_eq!(operands(&app), 2, "the fill and the outlined stroke");
+        let id = app.run("object.pathfinder.unite", json!({})).unwrap()["ids"][0].as_u64().unwrap();
+        let united = app.session.active().unwrap().doc.node(NodeId(id)).unwrap();
+        assert!(matches!(united.kind, NodeKind::Path { .. }), "one path, the stroke's inner edge gone: {:?}", united.kind);
+        let b = united.geometric_bounds().unwrap();
+        assert_eq!((b.x0, b.y0, b.x1, b.y1), (5.0, 5.0, 65.0, 65.0), "the stroke's outer edge");
+    }
+}