diff --git a/ROADMAP.md b/ROADMAP.md
index b04c4b69..b6549bd4 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -148,6 +148,7 @@ app's JSON control channel (`deckcraft --control PORT`).
 | 2026-10-18 | Find (Ctrl+F): "Find what:" has the keyboard as soon as the dialog opens, and keeps it after Enter finds a match, so the search can be typed and changed without clicking the field (#951) |
 | 2026-10-24 | Columns dialog: Home › Columns › More Columns… and Format Shape › Text Box › Columns… set the number of text columns (1 to 16) and the spacing between them in inches, in one undo step; `format.columns` with no fields opens it, and a key left out keeps the text box's own value |
 | 2026-10-18 | Duplicate (Ctrl+D) repeats a move: duplicate a shape, move the copy, and the next Duplicate places its copy the same distance further on, as in PowerPoint (#966) |
+| 2026-10-26 | Duplicate (Ctrl+D) names the copy as PowerPoint does: a shape with an automatic name ("Rectangle 1") gets the next one ("Rectangle 5", also for the shapes inside a duplicated group), and a name you chose ("Hero") stays as it is instead of becoming "Hero copy" |
 | 2026-10-22 | Slide Show: while animations play, each frame draws only the slide's shapes over the slide's backdrop (background, master and layout graphics), rendered once and ahead of time. A full-slide picture with a glow in the layout re-rendered at every frame held animations to 2–3 frames a second (~390 ms a frame at 1080p); now ~28 ms |
 | 2026-10-22 | Animation Pane ▸ Play From: with an effect selected, the pane's play button starts the canvas preview at that effect, with the effects before it already played. With nothing selected it is still Play All |
 | 2026-10-21 | Opening a .pptx puts the text of shapes without an anchor at the top even when the theme's shape defaults (`spDef`) centre new shapes, as PowerPoint for Mac draws them; checked with a synthetic probe and on a private 166-deck corpus (51 slides closer to PowerPoint's PDF, none further) |
diff --git a/crates/engine/src/cmd/edit.rs b/crates/engine/src/cmd/edit.rs
index b098503c..3ce31937 100644
--- a/crates/engine/src/cmd/edit.rs
+++ b/crates/engine/src/cmd/edit.rs
@@ -508,6 +508,19 @@ fn paste_text(s: &mut Session, p: &Value) -> Result<Value> {
     paste_plain(s, &t)
 }
 
+/// Duplicate gives a copy the next automatic name ("Rectangle 4" after "Rectangle 1"), as
+/// PowerPoint does, and keeps a name the user chose. PowerPoint tells the two apart by comparing
+/// the number with the shape's id; ids here are numbered across the deck, so any "{kind} {n}"
+/// counts as automatic.
+fn rename_automatic(sh: &mut Shape, taken: &mut std::collections::HashSet<String>) {
+    let base = if sh.is_group() { "Group".to_string() } else { super::insert::auto_name_base(sh) };
+    let n = sh.name.strip_prefix(&base).and_then(|r| r.strip_prefix(' '));
+    if n.is_some_and(|n| !n.is_empty() && n.bytes().all(|b| b.is_ascii_digit())) {
+        sh.name = super::insert::first_free_name(&base, taken);
+        taken.insert(sh.name.clone());
+    }
+}
+
 fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
     let ids = targets(s, p)?;
     let off = s.prefs.duplicate_offset;
@@ -532,6 +545,8 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
             })
             .unwrap_or((off, off));
         reid("edit.duplicate", doc, &mut copies)?;
+        let mut taken = super::current_names(doc, sel);
+        walk_mut(&mut copies, &mut |c| rename_automatic(c, &mut taken));
         for (c, b) in copies.iter_mut().zip(boxes) {
             let mut x = b;
             x.x += dx;
@@ -540,9 +555,6 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
             if sel.target == crate::Target::Slides {
                 c.ph = None;
             }
-            if !c.name.is_empty() {
-                c.name = format!("{} copy", c.name.trim_end_matches(" copy"));
-            }
         }
         let new_ids: Vec<ShapeId> = copies.iter().map(|c| c.id).collect();
         let shapes = crate::shapes_mut(doc, sel).ok_or_else(|| bad("edit.duplicate", "no slide"))?;
diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index 4dfc21f4..f182870f 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -237,6 +237,61 @@ fn pasted_shapes_get_the_next_automatic_name() {
     assert_eq!(names(&s).last().unwrap(), "Hero");
 }
 
+/// PowerPoint 16.0 (Windows): on "Rectangle 1, Oval 2, TextBox 3, Hero" Duplicate gives
+/// "Rectangle 5" and then "Rectangle 6", "TextBox 7"; the copy of "Hero" (and of its copy) is
+/// "Hero". Never "Hero copy".
+#[test]
+fn duplicate_gives_the_next_automatic_name_and_keeps_a_chosen_one() {
+    let mut s = session();
+    let names = |s: &Session| s.doc().unwrap().current_slide().unwrap().shapes.iter().map(|x| x.name.clone()).collect::<Vec<_>>();
+    let add = |s: &mut Session, cmd: &str, p: serde_json::Value| {
+        s.execute(cmd, &p).unwrap();
+        s.doc().unwrap().selection.shapes[0].0
+    };
+    let rect = add(&mut s, "shape.insert", json!({"preset": "rect", "rect": [10, 10, 50, 50]}));
+    let tb = add(&mut s, "shape.insert", json!({"preset": "rect", "rect": [100, 10, 50, 50]}));
+    s.execute("shape.rename", &json!({"id": tb, "name": "Hero"})).unwrap();
+    let n = names(&s).len();
+    let auto = names(&s)[n - 2].clone();
+    let (base, _) = auto.rsplit_once(' ').unwrap();
+
+    s.execute("edit.duplicate", &json!({"ids": [rect]})).unwrap();
+    s.execute("edit.duplicate", &json!({"ids": [rect]})).unwrap();
+    let all = names(&s);
+    assert_eq!(all[n], format!("{base} {}", n + 1), "{all:?}");
+    assert_eq!(all[n + 1], format!("{base} {}", n + 2), "{all:?}");
+
+    s.execute("edit.duplicate", &json!({"ids": [tb]})).unwrap();
+    let copy = s.doc().unwrap().selection.shapes[0].0;
+    s.execute("edit.duplicate", &json!({"ids": [copy]})).unwrap();
+    let all = names(&s);
+    assert_eq!(&all[n + 2..], ["Hero", "Hero"], "{all:?}");
+}
+
+#[test]
+fn duplicating_a_group_renames_its_automatic_children() {
+    let mut s = session();
+    let mut ids = vec![];
+    for x in [10, 100] {
+        s.execute("shape.insert", &json!({"preset": "rect", "rect": [x, 10, 50, 50]})).unwrap();
+        ids.push(s.doc().unwrap().selection.shapes[0].0);
+    }
+    s.execute("arrange.group", &json!({"ids": ids})).unwrap();
+    let group = s.doc().unwrap().selection.shapes[0].0;
+    s.execute("edit.duplicate", &json!({"ids": [group]})).unwrap();
+    let doc = s.doc().unwrap();
+    let shapes = &doc.current_slide().unwrap().shapes;
+    let (orig, copy) = (&shapes[shapes.len() - 2], &shapes[shapes.len() - 1]);
+    assert!(orig.is_group() && copy.is_group());
+    assert_ne!(orig.name, copy.name);
+    assert!(copy.name.starts_with("Group "), "{}", copy.name);
+    let all: Vec<_> = orig.children().iter().chain(copy.children()).map(|c| c.name.as_str()).collect();
+    let mut unique = all.clone();
+    unique.sort();
+    unique.dedup();
+    assert_eq!(unique.len(), all.len(), "{all:?}");
+}
+
 #[test]
 fn pasting_after_a_deleted_shape_does_not_repeat_a_name() {
     let mut s = session();