diff --git a/README.md b/README.md
index cc9ac54..508cc7c 100644
--- a/README.md
+++ b/README.md
@@ -228,7 +228,7 @@ You can set certain environment variables to control pyenv-virtualenv.
   `virtualenv`, download `get_pip.py` from the specified URL.
 * `PIP_VERSION`, if set and `venv` is preferred
   over `virtualenv`, install the specified version of pip.
-
+* `PYENV_VIRTUALENV_VERBOSE_ACTIVATE`, if set, shows some verbose outputs on activation and deactivation
 
 ## Version History