diff --git a/server/plugins-available/nginx_plugin.inc.php b/server/plugins-available/nginx_plugin.inc.php
index 01c9e5cc3a3f7be42d88ae4cb68db60e3a5e84de..4d8ac0aa5db1410327456a199d5a0c6b4ea4d5d6 100644
--- a/server/plugins-available/nginx_plugin.inc.php
+++ b/server/plugins-available/nginx_plugin.inc.php
@@ -1108,6 +1108,8 @@ class nginx_plugin {
 									case 'off':
 									case '1':
 									case '0':
+										// PHP-FPM might complain about invalid boolean value if you use 0
+										$value = 'off';
 									case 'true':
 									case 'false':
 									case 'yes':