diff --git a/etc/inc/upgrade_config.inc b/etc/inc/upgrade_config.inc
index 5c8bd08235..2bffa83e59 100644
--- a/etc/inc/upgrade_config.inc
+++ b/etc/inc/upgrade_config.inc
@@ -2238,16 +2238,24 @@ function rename_field(& $section, $oldname, $newname) {
 
 function upgrade_071_to_072() {
 	global $config;
-	rename_field($config['sysctl']['item'], 'desc', 'descr');
+	if (is_array($config['sysctl']) && is_array($config['sysctl']['item']))
+		rename_field($config['sysctl']['item'], 'desc', 'descr');
 }
 
 function upgrade_072_to_073() {
 	global $config;
-	rename_field($config['load_balancer']['monitor_type'], 'desc', 'descr');
-	rename_field($config['load_balancer']['lbpool'], 'desc', 'descr');
-	rename_field($config['load_balancer']['lbaction'], 'desc', 'descr');
-	rename_field($config['load_balancer']['lbprotocol'], 'desc', 'descr');
-	rename_field($config['load_balancer']['virtual_server'], 'desc', 'descr');
+	if (!is_array($config['load_balancer']))
+		return;
+	if (is_array($config['load_balancer']['monitor_type']))
+		rename_field($config['load_balancer']['monitor_type'], 'desc', 'descr');
+	if (is_array($config['load_balancer']['lbpool']))
+		rename_field($config['load_balancer']['lbpool'], 'desc', 'descr');
+	if (is_array($config['load_balancer']['lbaction']))
+		rename_field($config['load_balancer']['lbaction'], 'desc', 'descr');
+	if (is_array($config['load_balancer']['lbprotocol']))
+		rename_field($config['load_balancer']['lbprotocol'], 'desc', 'descr');
+	if (is_array($config['load_balancer']['virtual_server']))
+		rename_field($config['load_balancer']['virtual_server'], 'desc', 'descr');
 }
 
 function upgrade_073_to_074() {
@@ -2257,8 +2265,11 @@ function upgrade_073_to_074() {
 
 function upgrade_074_to_075() {
 	global $config;
-	rename_field($config['ca'], 'name', 'descr');
-	rename_field($config['cert'], 'name', 'descr');
-	rename_field($config['crl'], 'name', 'descr');
+	if (is_array($config['ca']))
+		rename_field($config['ca'], 'name', 'descr');
+	if (is_array($config['cert']))
+		rename_field($config['cert'], 'name', 'descr');
+	if (is_array($config['crl']))
+		rename_field($config['crl'], 'name', 'descr');
 }
 ?>