diff --git a/tetras_extraction/macao_12/script/extract_page.py b/tetras_extraction/macao_12/script/extract_page.py
index 733a6e396bc230b01680e964cd2d72206a171f43..ff3711724697eef2714865cf4a7c1f5a7ca67f74 100644
--- a/tetras_extraction/macao_12/script/extract_page.py
+++ b/tetras_extraction/macao_12/script/extract_page.py
@@ -89,7 +89,7 @@ class RegexParser:
             m = re.match(r"var nr = (\d+);", line)
             if m is not None:
                 # "index" line
-                index = int(m.group(1))
+                index = int(m.group(1)) - 1  # question indexes start at 1
             elif line == "exo.tabStylesR[nr] = CODE_F;":
                 # "incorrect answer" line
                 insert_grow(correct_choices, index, False, fill_value=False)
@@ -153,7 +153,7 @@ class XpathParser:
             value = e.xpath("@value")
             if len(value) != 0:
                 # "index line"
-                index = int(value[0])
+                index = int(value[0]) - 1  # question indexes start at 1
             else:
                 # "correct" or "incorrect" line
                 correct = e.get("name") == "CODE_V"