diff --git a/ci-support.sh b/ci-support.sh
index 47ac5a52348939a66f415677ea973e7ba9d6cdef..bb3a7e38ee72a898a37c5f402c9e57e4663f5a91 100644
--- a/ci-support.sh
+++ b/ci-support.sh
@@ -130,7 +130,7 @@ def main():
         parser.print_usage()
         sys.exit(1)
 
-    with open(args.filename, encoding="utf-8") as toml:
+    with open(args.filename, "rb") as toml:
         data = tomllib.load(toml)
 
     sys.exit(args.func(data, args))