diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index 6e37058dd..ad740e3f6 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -652,11 +652,15 @@ impl Session {
     /// is rolled back and its error is returned. Groups nest; the outermost one makes the step.
     pub fn grouped<R>(&mut self, label: &str, f: impl FnOnce(&mut Session) -> Result<R>) -> Result<R> {
         let token = self.group_begin(label)?;
+        let doc = token.doc();
         match f(self) {
-            Ok(r) => {
-                self.group_end(token)?;
-                Ok(r)
-            }
+            Ok(r) => match self.group_end(token) {
+                Ok(_) => Ok(r),
+                // `f` closed the group's document (`file.close`, or `file.open` taking the place of
+                // an untouched new workbook), and the group went with it: nothing is left to undo.
+                Err(_) if !self.docs.iter().any(|d| d.uid == doc) => Ok(r),
+                Err(e) => Err(e),
+            },
             Err(e) => {
                 // The error from `f` is the one to report. A rollback fails only when the group
                 // has already ended, and then there is nothing left to undo.
diff --git a/crates/engine/src/tests/seams.rs b/crates/engine/src/tests/seams.rs
index 3216cfd97..a5cd0d868 100644
--- a/crates/engine/src/tests/seams.rs
+++ b/crates/engine/src/tests/seams.rs
@@ -170,6 +170,27 @@ fn a_long_group_keeps_the_history_before_it() {
     assert_eq!(d.undo.iter().filter(|e| e.label == "Enter Cell").count(), 99);
 }
 
+#[test]
+fn a_grouped_action_that_closes_its_document_succeeds() {
+    // The group goes with the document; the action did what it was asked.
+    let mut s = s();
+    let uid = s.doc().unwrap().uid;
+    s.grouped("Close", |s| s.execute("file.close", json!({}))).unwrap();
+    assert!(s.docs.iter().all(|d| d.uid != uid) && !s.in_group(uid));
+    // Opening a file into an untouched new workbook takes its place the same way.
+    s.new_workbook();
+    let uid = s.doc().unwrap().uid;
+    let bytes = serde_json::to_vec(&gridcraft_model::Workbook::new()).unwrap();
+    s.grouped("Open", |s| s.execute("file.open", json!({"name": "theirs.json", "base64": crate::io::base64_encode(&bytes)}))).unwrap();
+    assert!(s.docs.iter().all(|d| d.uid != uid) && !s.in_group(uid) && s.groups.is_empty());
+    // A group ended by someone else while its document is still open is still an error.
+    let err = s.grouped("Ended", |s| {
+        let token = s.groups.last().map(|g| crate::GroupToken { id: g.id, doc: g.doc });
+        s.group_end(token.ok_or_else(|| EngineError::Other("no group".into()))?).map(|_| ())
+    });
+    assert!(err.unwrap_err().to_string().contains("already ended"));
+}
+
 #[test]
 fn closing_a_document_drops_its_groups() {
     let mut s = s();