diff --git a/nginx/files/proxy.conf b/nginx/files/proxy.conf
index ea53ffb..4fb0597 100644
--- a/nginx/files/proxy.conf
+++ b/nginx/files/proxy.conf
@@ -49,7 +49,7 @@
       {%- endif %}
 
       {%- if site.proxy.filter is defined %}
-      sub_filter '{{ site.proxy.filter.search }}' '{{ site.proxy.filter.replace }}';
+      sub_filter '{{ site.proxy.filter.search }}' {% if site.proxy.filter.replace == '$server_addr' %}$server_addr{% else %}'{{ site.proxy.filter.replace }}'{% endif %};
       sub_filter_types *;
       sub_filter_once off;
       {%- endif %}