-uschar *alias_arg = NULL;
-uschar *called_as = US"";
-uschar *cmdline_syslog_name = NULL;
-uschar *start_queue_run_id = NULL;
-uschar *stop_queue_run_id = NULL;
-uschar *expansion_test_message = NULL;
+const uschar *alias_arg = NULL;
+const uschar *called_as = US"";
+const uschar *cmdline_syslog_name = NULL;
+const uschar *start_queue_run_id = NULL;
+const uschar *stop_queue_run_id = NULL;
+const uschar *expansion_test_message = NULL;