diff --git a/templates/nginx-proxy-params.conf.j2 b/templates/nginx-proxy-params.conf.j2
index 900ce90..4843561 100644
--- a/templates/nginx-proxy-params.conf.j2
+++ b/templates/nginx-proxy-params.conf.j2
@@ -3,7 +3,7 @@
 proxy_http_version 1.1;
 proxy_set_header Connection "";
 {% if haproxy_ips is defined %}
-{% if not nginx_proxy_define_header_host %}
+{% if nginx_proxy_define_header_host %}
 proxy_set_header Host $http_host;
 {% endif %}
 {% if nginx_behind_haproxy_settings %}
@@ -12,7 +12,7 @@ proxy_set_header X-Forwarded-Host {{ nginx_x_forwarded_host }};
 proxy_set_header X-Forwarded-Server $host;
 {% endif %}
 {% else %}
-{% if not nginx_proxy_define_header_host %}
+{% if nginx_proxy_define_header_host %}
 proxy_set_header Host $host;
 {% endif %}
 {% if nginx_define_x_real_ip %}