diff --git a/README.md b/README.md
index fd99e92..087b86e 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,11 @@ Value of `pm.max_children`.
 
 Value of `pm.start_servers`
 
+## PHP_MAX_SPARE_SERVERS
+- default: Value of PHP_START_SERVERS or 3
+
+Value of `pm.max_spare_servers`
+
 ## PHP_ADMIN_VALUES
 Comma seperated list of php admin values.
 
diff --git a/rootfs/etc/confd/templates/www.conf.tmpl b/rootfs/etc/confd/templates/www.conf.tmpl
index d0c988b..8745209 100644
--- a/rootfs/etc/confd/templates/www.conf.tmpl
+++ b/rootfs/etc/confd/templates/www.conf.tmpl
@@ -128,7 +128,7 @@ pm.min_spare_servers = 1
 ; The desired maximum number of idle server processes.
 ; Note: Used only when pm is set to 'dynamic'
 ; Note: Mandatory when pm is set to 'dynamic'
-pm.max_spare_servers = 3
+pm.max_spare_servers = {{ getenv "PHP_MAX_SPARE_SERVERS" (getenv "PHP_START_SERVERS" "3") }}
 
 ; The number of seconds after which an idle process will be killed.
 ; Note: Used only when pm is set to 'ondemand'