diff --git a/main.py b/main.py
index b779fda..3bbb1eb 100644
--- a/main.py
+++ b/main.py
@@ -55,7 +55,10 @@ def download_and_parse():
     global products_cache, last_refresh
     resp = requests.get(EXCEL_URL, timeout=60)
     resp.raise_for_status()
-    wb = load_workbook(BytesIO(resp.content), read_only=True, data_only=True)
+    # read_only=True would stop at the sheet's declared dimension attribute, silently
+    # missing any rows MTZ added beyond the original range. Since the file is already
+    # in memory (BytesIO), read_only gives no I/O benefit and data_only=True suffices.
+    wb = load_workbook(BytesIO(resp.content), data_only=True)
     ws = wb.active
     rows = list(ws.iter_rows(min_row=6, values_only=True))
     parsed = []