diff --git a/README.md b/README.md
index 16107d0..ace98ae 100644
--- a/README.md
+++ b/README.md
@@ -122,6 +122,7 @@ Then you can control the locations via XDG environment variables as such:
 * `XDG_DATA_HOME`: GHCs will be unpacked in `ghcup/ghc` subdir
 * `XDG_CACHE_HOME`: logs and download files will be stored in `ghcup` subdir
 * `XDG_BIN_HOME`: binaries end up here (default: `~/.local/bin`)
+* `XDG_CONFIG_HOME`: the config file is stored in `ghcup` subdir as `config.yaml` (default: `~/.config`)
 
 ### Installing custom bindists