diff --git a/docs/installation.md b/docs/installation.md
index 32e1fa8d6..f951ef3aa 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -130,10 +130,14 @@ volumes:
 
 #### Multiple configuration files
 
-For complex setups, splitting the configuration between multiple YAML files might be desired. In this case, folder containing YAML files is passed on startup, Blocky will join all the files in alphabetic order and load the configuration.
+For complex setups, splitting the configuration between multiple YAML files might be desired. In this case, folder containing YAML files is passed on startup, Blocky will join all the files.
 
 `./blocky --config ./config/`
 
+!!! warning
+
+    Blocky simply joins the multiple YAML files. If a directive (e.g. `upstream`) is repeated in multiple files, the configuration will not load and start will fail.
+
 ## Other installation types
 
 !!! warning