diff --git a/templates/etc-apache2-sites-available-sd-agent b/templates/etc-apache2-sites-available-sd-agent
index 32cfe8ee24f4189c4156fcf35daecb0649360120..f0f5ea0ffb27e8d8ce3d323ef36646b786bacf1b 100644
--- a/templates/etc-apache2-sites-available-sd-agent
+++ b/templates/etc-apache2-sites-available-sd-agent
@@ -12,7 +12,7 @@
 
   SetEnvIf X-Forwarded-For "^.*\..*\..*\..*" forwarded
   LogLevel warn
-{% if apache_version == '2.4' %}
+{% if apache_version|default('2.4') == '2.4' %}
   ErrorLogFormat "[%{u}t] [%l] [pid %P] [client\ %{X-Forwarded-For}i] %M% ,\ referer:\ %{Referer}i"
 {% endif %}
   LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" proxy