diff --git a/php/variant-fpm.md b/php/variant-fpm.md
index 5093b6ce2..06ba66065 100644
--- a/php/variant-fpm.md
+++ b/php/variant-fpm.md
@@ -11,3 +11,5 @@ Some potentially helpful resources:
 -	[very detailed article by Pascal Landau](https://www.pascallandau.com/blog/php-php-fpm-and-nginx-on-docker-in-windows-10/)
 -	[Stack Overflow discussion](https://stackoverflow.com/q/29905953/433558)
 -	[Apache httpd Wiki example](https://wiki.apache.org/httpd/PHPFPMWordpress)
+
+**WARNING:** the FastCGI protocol is inherently trusting, and thus *extremely* insecure to expose outside of a private container network -- unless you know *exactly* what you are doing (and are willing to accept the extreme risk), do not use Docker's `--publish` (`-p`) flag with this image variant.