diff --git a/installinstallmacos.py b/installinstallmacos.py
index e6f4d1f..9876e5d 100755
--- a/installinstallmacos.py
+++ b/installinstallmacos.py
@@ -60,7 +60,7 @@ DEFAULT_SUCATALOGS = {
     "index-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9"
     "-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog",
     "21": "https://swscan.apple.com/content/catalogs/others/"
-    "index-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9"
+    "index-12-10.16-10.15-10.14-10.13-10.12-10.11-10.10-10.9"
     "-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog",
 }