diff --git a/changelog.d/5397.doc b/changelog.d/5397.doc
new file mode 100644
index 0000000000..c2b500b482
--- /dev/null
+++ b/changelog.d/5397.doc
@@ -0,0 +1 @@
+Add information about nginx normalisation to reverse_proxy.rst. Contributed by @skalarproduktraum - thanks!
diff --git a/docs/reverse_proxy.rst b/docs/reverse_proxy.rst
index e4b870411c..4b640ffc4f 100644
--- a/docs/reverse_proxy.rst
+++ b/docs/reverse_proxy.rst
@@ -48,6 +48,8 @@ Let's assume that we expect clients to connect to our server at
               proxy_set_header X-Forwarded-For $remote_addr;
           }
       }
+      
+  Do not add a `/` after the port in `proxy_pass`, otherwise nginx will canonicalise/normalise the URI.
 
 * Caddy::