diff --git a/source3/utils/net_conf.c b/source3/utils/net_conf.c
index e43cd121644..e8481b4d5f9 100644
--- a/source3/utils/net_conf.c
+++ b/source3/utils/net_conf.c
@@ -30,6 +30,7 @@
 #include "includes.h"
 #include "system/filesys.h"
 #include "utils/net.h"
+#include "utils/net_conf_util.h"
 #include "lib/smbconf/smbconf.h"
 #include "lib/smbconf/smbconf_init.h"
 #include "lib/smbconf/smbconf_reg.h"
@@ -788,6 +789,10 @@ static int net_conf_setparm(struct net_context *c, struct smbconf_ctx *conf_ctx,
 	}
 	value_str = argv[2];
 
+	if (!net_conf_param_valid(service,param, value_str)) {
+		goto done;
+	}
+
 	err = smbconf_transaction_start(conf_ctx);
 	if (!SBC_ERROR_IS_OK(err)) {
 		d_printf(_("error starting transaction: %s\n"),