diff --git a/README.markdown b/README.markdown
index 9c72a8c594..96c01ebba3 100644
--- a/README.markdown
+++ b/README.markdown
@@ -5253,7 +5253,7 @@ ngx.req.set_uri
 
 **context:** *set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua**
 
-Rewrite the current request's (parsed) URI by the `uri` argument. The `uri` argument must be a Lua string and cannot be of zero length, or a Lua exception will be thrown.
+Rewrite the current request's (parsed) URI by the `uri` argument. The `uri` argument must be a Lua string and cannot be of zero length, or a Lua exception will be thrown.  After this function has been called, [ngx.req.is_internal](#ngxreqis_internal) will evaluate to true, even if this request came from a client.
 
 The optional boolean `jump` argument can trigger location rematch (or location jump) as [ngx_http_rewrite_module](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html)'s [rewrite](http://nginx.org/en/docs/http/ngx_http_rewrite_module.html#rewrite) directive, that is, when `jump` is `true` (default to `false`), this function will never return and it will tell Nginx to try re-searching locations with the new URI value at the later `post-rewrite` phase and jumping to the new location.