diff --git a/defaults/main.yml b/defaults/main.yml
index 854145a..7d6c17a 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -53,9 +53,9 @@ nginx_set_original_uri: True
 nginx_proxy_buffering: "on"
 nginx_proxy_redirect: "off"
 nginx_x_forwarded_host: "$remote_addr"
-nginx_proxy_buffer_size: {{ nginx_default_max_buffers_size * 8 }}
+nginx_proxy_buffer_size: '{{ nginx_default_max_buffers_size * 8 }}'
 nginx_proxy_buffers: '4 {{ nginx_proxy_buffer_size }}k'
-nginx_proxy_busy_buffers_size: {{ nginx_proxy_buffer_size * 2 }}
+nginx_proxy_busy_buffers_size: '{{ nginx_proxy_buffer_size * 2 }}'
 nginx_proxy_connect_timeout: 30s
 nginx_proxy_read_timeout: 480s
 nginx_proxy_send_timeout: 120s