diff --git a/crates/engine/src/cmd/insert.rs b/crates/engine/src/cmd/insert.rs
index 392c5ee..8e0434a 100644
--- a/crates/engine/src/cmd/insert.rs
+++ b/crates/engine/src/cmd/insert.rs
@@ -349,6 +349,9 @@ fn table_flag(s: &mut Session, p: &Json, which: &str) -> Result<Json> {
             "totals" => {
                 let v = on.unwrap_or(!t.totals_row);
                 if v != t.totals_row {
+                    if v && t.range.end.row.saturating_add(1) >= MAX_ROWS {
+                        return Err(EngineError::Other("There's no room below the table for the total row.".into()));
+                    }
                     t.totals_row = v;
                     if v {
                         t.range.end.row += 1;
diff --git a/crates/engine/tests/table_total_row_last_row.rs b/crates/engine/tests/table_total_row_last_row.rs
new file mode 100644
index 0000000..eb1bd3d
--- /dev/null
+++ b/crates/engine/tests/table_total_row_last_row.rs
@@ -0,0 +1,34 @@
+use gridcraft_core::{CellRef, MAX_ROWS};
+use gridcraft_engine::Session;
+use serde_json::json;
+
+fn refused(range: &str) {
+    let mut s = Session::new();
+    s.new_workbook();
+    s.execute("insert.table", json!({"range": range, "header": true})).unwrap();
+    let before = s.doc().unwrap().wb.active().unwrap().tables[0].clone();
+    assert!(s.execute("table.totalRow", json!({"on": true, "table": &before.name})).is_err(), "{range}");
+    let sh = s.doc().unwrap().wb.active().unwrap();
+    assert_eq!(sh.tables[0].range, before.range, "{range}");
+    assert_eq!(sh.tables[0].range.end.row, MAX_ROWS - 1, "{range}");
+    assert!(!sh.tables[0].totals_row, "{range}");
+    assert!(sh.value(CellRef::new(MAX_ROWS, 0)).is_empty(), "{range}");
+}
+
+#[test]
+fn total_row_is_refused_on_a_table_ending_at_the_last_worksheet_row() {
+    refused("A1048575:B1048576");
+    refused("A1048576:B1048576");
+}
+
+#[test]
+fn total_row_still_grows_an_ordinary_table() {
+    let mut s = Session::new();
+    s.new_workbook();
+    s.execute("range.setValues", json!({"range": "A1", "values": [["Item", "Amount"], ["a", 2], ["b", 3]]})).unwrap();
+    s.execute("insert.table", json!({"range": "A1:B3", "header": true})).unwrap();
+    s.execute("table.totalRow", json!({"on": true, "table": "Table1"})).unwrap();
+    let t = &s.doc().unwrap().wb.active().unwrap().tables[0];
+    assert!(t.totals_row);
+    assert_eq!(t.range.end.row, 3);
+}