diff --git a/customers/base/script-configmap.yml b/customers/base/script-configmap.yml
index 8371521..dd46939 100644
--- a/customers/base/script-configmap.yml
+++ b/customers/base/script-configmap.yml
@@ -5,8 +5,7 @@ metadata:
 data:
   nc-upgrade: |
     #!/bin/bash
-    sed "s/config_is_read_only\(.\) => true,/config_is_read_only\1 => false,/" /var/www/html/config/config.php > /var/www/html/config/config.php.tmp
-    mv /var/www/html/config/config.php.tmp /var/www/html/config/config.php
+    sed -i "s/config_is_read_only\(.\) => true,/config_is_read_only\1 => false,/" /var/www/html/config/config.php
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ app:disable globalsiteselector
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ upgrade
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ app:enable globalsiteselector
@@ -15,5 +14,4 @@ data:
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ db:add-missing-primary-keys
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ db:add-missing-columns
     php -d apc.enable_cli=1 -d memory_limit=-1 /var/www/html/occ db:add-missing-indices
-    sed "s/config_is_read_only\(.\) => false,/config_is_read_only\1 => true,/" /var/www/html/config/config.php > /var/www/html/config/config.php.tmp
-    mv /var/www/html/config/config.php.tmp /var/www/html/config/config.php
+    sed -i "s/config_is_read_only\(.\) => false,/config_is_read_only\1 => true,/" /var/www/html/config/config.php