diff --git a/doc/en/example/simple.rst b/doc/en/example/simple.rst
index b9f3daecc..5e5134c70 100644
--- a/doc/en/example/simple.rst
+++ b/doc/en/example/simple.rst
@@ -269,6 +269,7 @@ running from a test you can do something like this:
         sys._called_from_test = True
 
     def pytest_unconfigure(config):
+        import sys
         del sys._called_from_test
 
 and then check for the ``sys._called_from_test`` flag: