diff --git a/src/acl.c b/src/acl.c
index efd1ee662..6a23bae86 100644
--- a/src/acl.c
+++ b/src/acl.c
@@ -1135,6 +1135,8 @@ struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *
 			expr->args[0].data.str.str = strdup("");
 			expr->args[0].data.str.len = 1;
 			expr->args[0].data.str.len = 0;
+			arg_list_add(al, &expr->args[0], 0);
+
 			expr->args[1].type = ARGT_STOP;
 		}
 		else if (ARGM(expr->smp->arg_mask)) {