diff --git a/doc/single_host/demoCA/index.txt.attr.old b/doc/single_host/demoCA/index.txt.attr.old
new file mode 100644
index 0000000..8f7e63a
--- /dev/null
+++ b/doc/single_host/demoCA/index.txt.attr.old
@@ -0,0 +1 @@
+unique_subject = yes