diff --git a/crates/engine/src/io.rs b/crates/engine/src/io.rs
index b6a5d8473..b7a5ea709 100644
--- a/crates/engine/src/io.rs
+++ b/crates/engine/src/io.rs
@@ -166,7 +166,10 @@ fn read_plain(name: &str, bytes: &[u8], csv_as_text: bool) -> Result<(Workbook,
             let mut wb: Workbook = serde_json::from_slice(bytes).map_err(|e| EngineError::Other(format!("not a GridCraft JSON workbook: {e}")))?;
             wb.styles.rebuild_index();
             if wb.sheets.is_empty() {
+                // The file's macros are read after this (`macros::load`), so they come along.
+                let macros = std::mem::take(&mut wb.macros_read);
                 wb = Workbook::new();
+                wb.macros_read = macros;
             }
             // The file's band placement and cell count are derived state: rebuild them from the
             // cells themselves, dropping what is outside the sheet grid (#1008).
diff --git a/crates/engine/src/macros/tests.rs b/crates/engine/src/macros/tests.rs
index d30ff021d..957b738f5 100644
--- a/crates/engine/src/macros/tests.rs
+++ b/crates/engine/src/macros/tests.rs
@@ -514,3 +514,16 @@ fn naming_clashing_macros_takes_linear_work() {
     taken.insert("a (2)");
     assert_eq!(taken.unique("a"), "a (4)");
 }
+
+#[test]
+fn a_json_workbook_with_no_sheets_keeps_its_macros() {
+    // A JSON file with an empty sheet list opens as a new workbook; its macros come along.
+    let mut wb = Workbook::new();
+    wb.macros.push(sample_macro("A"));
+    let mut v: serde_json::Value = serde_json::from_slice(&crate::io::save_bytes(&wb, "book.json").unwrap()).unwrap();
+    v["sheets"] = json!([]);
+    let (back, warnings) = crate::io::open_bytes("book.json", v.to_string().as_bytes()).unwrap();
+    assert!(warnings.is_empty(), "{warnings:?}");
+    assert_eq!(back.sheets.len(), 1);
+    assert_eq!(back.macros, wb.macros);
+}