diff --git a/etc/rc.dyndns.update b/etc/rc.dyndns.update
index ac56f3562..b350c224b 100755
--- a/etc/rc.dyndns.update
+++ b/etc/rc.dyndns.update
@@ -37,7 +37,7 @@ require_once("shaper.inc");
 
 /* Interface IP address has changed */
 
-if (isset($_GET))
+if (isset($_GET['dyndns']))
 	$argument = $_GET['dyndns'];
 else
 	$argument = trim($argv[1], " \n");
diff --git a/etc/rc.interfaces_wan_configure b/etc/rc.interfaces_wan_configure
index fbdc5e437..c291ee8ad 100755
--- a/etc/rc.interfaces_wan_configure
+++ b/etc/rc.interfaces_wan_configure
@@ -34,7 +34,7 @@ require_once("functions.inc");
 require_once("filter.inc");	
 require_once("shaper.inc");	
 
-if (isset($_GET))
+if (isset($_GET['interface']))
 	$argument = $_GET['interface'];
 else
 	$argument = str_replace("\n", "", $argv[1]);
diff --git a/etc/rc.linkup b/etc/rc.linkup
index 6f7d1589a..bff0c552b 100755
--- a/etc/rc.linkup
+++ b/etc/rc.linkup
@@ -85,7 +85,7 @@ function handle_argument_group($iface, $argument2) {
 
 global $g;
 if (!file_exists("{$g['varrun_path']}/booting") && empty($g['booting'])) {
-if (isset($_GET)) {
+if (isset($_GET['interface'])) {
 	if (!empty($_GET['interface']))
 		handle_argument_group($_GET['interface'], $_GET['action']);
 } else {
diff --git a/etc/rc.openvpn b/etc/rc.openvpn
index 3148e4f22..086aa490b 100755
--- a/etc/rc.openvpn
+++ b/etc/rc.openvpn
@@ -71,7 +71,7 @@ if (file_exists("{$g['varrun_path']}/booting"))
 	return;
 
 /* Input argument is a comma-separated list of gateway names, blank or "all". */
-if (isset($_GET))
+if (isset($_GET['interface']))
 	$argument = $_GET['interface'];
 else
 	$argument = trim($argv[1], " \n");