diff --git a/doc/manual/src/configuration.md b/doc/manual/src/configuration.md
index 02210449f..00409a091 100644
--- a/doc/manual/src/configuration.md
+++ b/doc/manual/src/configuration.md
@@ -63,7 +63,7 @@ following:
         .. other configuration ..
         location /hydra/ {
 
-            proxy_pass     http://127.0.0.1:3000;
+            proxy_pass     http://127.0.0.1:3000/;
             proxy_redirect http://127.0.0.1:3000 https://example.com/hydra;
 
             proxy_set_header  Host              $host;
@@ -74,6 +74,8 @@ following:
         }
     }
 
+Note that the trailing slash at the end of proxy_pass is significant and must not be omitted!
+
 Statsd Configuration
 --------------------