diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index 1dc9196d4..80bcfd5ae 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -469,8 +469,10 @@ impl Session {
                     d.undo.truncate(len);
                 }
                 d.undo.push(HistoryEntry { label, wb, selection: sel });
+                d.redo.clear();
             }
-            d.redo.clear();
+            // Inside a group the redo history waits for the group: `group_end` clears it when the
+            // group becomes a step, and `group_rollback` puts it back as it was.
             d.revision += 1;
         }
         // The history limit applies once the outermost command has collapsed its steps, so the
diff --git a/crates/engine/src/tests/seams.rs b/crates/engine/src/tests/seams.rs
index e1aaaba67..b3397c724 100644
--- a/crates/engine/src/tests/seams.rs
+++ b/crates/engine/src/tests/seams.rs
@@ -226,6 +226,13 @@ fn register_group_commands() {
     });
     // A command that is one group keeps the group's name.
     register("test.onlyGroup", |s, _| s.grouped("Named Step", |s| put(s, "D1", "x")).map(|_| json!({})));
+    // An edit, then the rollback of the innermost group that was open before the command.
+    register("test.rollbackOpenGroup", |s, _| {
+        put(s, "E1", "gone")?;
+        let token = s.groups.last().map(|g| crate::GroupToken { id: g.id, doc: g.doc });
+        s.group_rollback(token.ok_or_else(|| EngineError::Other("no group".into()))?)?;
+        Ok(json!({}))
+    });
     // An edit, then the end of the innermost group that was open before the command.
     register("test.endOpenGroup", |s, _| {
         put(s, "E1", "end")?;
@@ -278,6 +285,25 @@ fn a_stale_group_step_does_not_name_a_later_command() {
     assert!(v(&s, "B2").is_empty() && v(&s, "D1").is_empty());
 }
 
+#[test]
+fn a_group_rolled_back_inside_a_command_keeps_the_redo_history() {
+    // The debugger's Stop with Undo Changes rolls its group back inside a command. The rollback
+    // put the redo history back, and the command's own bookkeeping then cleared it again.
+    register_group_commands();
+    let mut s = s();
+    set(&mut s, "A1", "first");
+    s.execute("edit.undo", json!({})).unwrap();
+    assert_eq!(s.doc().unwrap().redo.len(), 1);
+    let token = s.group_begin("Debug").unwrap();
+    set(&mut s, "B1", "inside");
+    s.execute("test.rollbackOpenGroup", json!({})).unwrap();
+    assert!(!s.in_group(token.doc));
+    assert!(v(&s, "B1").is_empty() && v(&s, "E1").is_empty());
+    assert_eq!(s.doc().unwrap().redo.len(), 1, "the redo history survives the rolled-back group");
+    s.execute("edit.redo", json!({})).unwrap();
+    assert_eq!(v(&s, "A1").display(), "first");
+}
+
 /// Fills the undo history to the limit with edits of Z1 ("v0" to "v99"), and returns its snapshots.
 fn fill_history(s: &mut Session) -> Vec<std::sync::Arc<gridcraft_model::Workbook>> {
     for i in 0..crate::UNDO_LIMIT {