diff --git a/package-source-builder/overlay/usr/bin/apertis-pkg-pull-updates b/package-source-builder/overlay/usr/bin/apertis-pkg-pull-updates
index 2ea3536d0e0d2ec7960b1cd592efd2d512ad23b2..4c4713920670e512118d90334e81d7391157da03 100755
--- a/package-source-builder/overlay/usr/bin/apertis-pkg-pull-updates
+++ b/package-source-builder/overlay/usr/bin/apertis-pkg-pull-updates
@@ -228,7 +228,10 @@ def main():
   parser.add_argument('--mirror', dest='mirror', type=str, required=True, help='the upstream mirror (e.g. http://deb.debian.org/debian)')
   args = parser.parse_args()
   package_name = args.package
-  upstream_suite = args.upstream
+  # buster-security → buster,
+  # buster-updates  → buster,
+  # buster          → buster
+  upstream_suite = args.upstream.split('-')[0]
   mirror = args.mirror
 
   package_name = args.package or get_package_name()