diff --git a/docs/configuration/entrypoints.md b/docs/configuration/entrypoints.md
index 29f9e4853..7f424e506 100644
--- a/docs/configuration/entrypoints.md
+++ b/docs/configuration/entrypoints.md
@@ -485,6 +485,13 @@ To enable IP white listing at the entry point level.
       # useXForwardedFor = true
 ```
 
+By setting the `useXForwardedFor` option, the `sourceRange` addresses will be matched against the request header `X-Forwarded-For` address list, from left to right.
+
+!!! danger
+    When using Traefik behind another load-balancer, its own internal address will be appended in the `X-Forwarded-For` header.
+    Be sure to carefully configure the `sourceRange` as adding the internal network CIDR,
+    or the load-balancer address directly, will cause all requests coming from it to pass through.
+
 ## ProxyProtocol
 
 To enable [ProxyProtocol](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) support.