diff --git a/lib/hx509/hxtool-commands.in b/lib/hx509/hxtool-commands.in
index 3977a5f9a..5d7e8fc9b 100644
--- a/lib/hx509/hxtool-commands.in
+++ b/lib/hx509/hxtool-commands.in
@@ -235,6 +235,11 @@ command = {
 }
 command = {
 	name = "pkcs10-create"
+	option = {
+		long = "subject"
+		type = "string"
+		help = "Subject DN"
+	}
 	option = {
 		long = "verbose"
 		type = "flag"