diff --git a/README.md b/README.md
index d4dafe4..9129223 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,9 @@
 pip install pylyzer
 ```
 
+If installed this way, type resolution for the standard libraries is not available.
+If you want to use it, you need to install [Erg](https://github.com/mtshiba/ergup).
+
 ### cargo (rust package manager)
 
 ```bash