diff --git a/How-to-config-file.md b/How-to-config-file.md
index fad77c0..1519799 100644
--- a/How-to-config-file.md
+++ b/How-to-config-file.md
@@ -1,3 +1,5 @@
+This only works with any version older than v4.0
+
 There is a config file template available with every release, which contains all available parameters for the corresponding release.
 
 To use the config file you need to pass `-c <path_to_config>`, e.g. `-c ./config.yaml`.