diff --git a/install-poetry.py b/install-poetry.py
index 9980ff5..2eb61b5 100644
--- a/install-poetry.py
+++ b/install-poetry.py
@@ -528,6 +528,10 @@ class Installer:
 
             virtualenv.cli_run([str(env_path), "--clear"])
 
+        # We add a special file so that Poetry can detect
+        # its own virtual environment
+        env_path.joinpath("poetry_env").touch()
+
         return env_path
 
     def make_bin(self, version: str) -> None: