IP地址不支持HTTP严格传输安全性

我使用nginx为IP地址设置了证书，并启用了HTTP严格传输安全性：

add_header  Strict-Transport-Security "max-age=31536000; includeSubdomains;";

该指令位于标题中

HTTP/1.1 200 OK
Server: nginx
Date: Wed, 17 Sep 2014 22:46:54 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Access-Control-Allow-Origin: *
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Strict-Transport-Security: max-age=31536000; includeSubdomains;
X-UA-Compatible: IE=Edge,chrome=1

...但是浏览器并不尊重它（相反，它们对于FQDN确实如此）。