diff --git a/README.md b/README.md
index 45a2e702..4fa446c7 100644
--- a/README.md
+++ b/README.md
@@ -43,6 +43,8 @@ It is combined with [EO](https://github.com/objectionary/eo) editor. EO is based
     cd back
     # for the first time
     direnv allow
+    # build for HLS
+    nix build
     # start the server
     nix run
     ```
@@ -59,4 +61,4 @@ It is combined with [EO](https://github.com/objectionary/eo) editor. EO is based
 - If in VS Code, reload the window (`Ctrl`+`Shift`+`P` -> `Developer: Reload window`) and repeat previous commands to start the server and the client
 
 - For Haskell, your shell will have [haskell-language-server](https://github.com/haskell/haskell-language-server)
-- For Purescript - [purescript-language-server](https://github.com/nwolverson/purescript-language-server)
\ No newline at end of file
+- For Purescript - [purescript-language-server](https://github.com/nwolverson/purescript-language-server)