diff --git a/FAQ.md b/FAQ.md
index a6485ac..b3adeea 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -46,7 +46,12 @@ Virtual libraries are implemented as searches in Calibre's own searching languag
 
 ### What is the maximum file-size which can be uploaded through calibre-web?
 
-Calibre-web default server ('tornado') limits the uploaded file size to 200MB, 'Gevent' the server from the optional requirement has no hardcoded limit (or nothing I'm aware of)
+Calibre-web default server ('tornado') limits the uploaded file size to 200MB, 'Gevent' the server from the optional requirement has no hardcoded limit (or nothing I'm aware of).
+
+
+### My file is smaller then 200MB, but I get a '413 - Request Entity To Large' error message
+
+If you are using some additional systems like a proxy or reverese proxy, they must be configured to support the file size as well. See [https://www.keycdn.com/support/413-request-entity-too-large](https://www.keycdn.com/support/413-request-entity-too-large) for a possible fix.
 
 
 ### Can Calibre-web execute malicious code in an epub?