Reference to PYTHONPATH should be PYTHONSTARTUP.
diff --git a/Doc/libuser.tex b/Doc/libuser.tex
index d90132c..b05e391 100644
--- a/Doc/libuser.tex
+++ b/Doc/libuser.tex
@@ -5,7 +5,7 @@
As a policy, Python doesn't run user-specified code on startup of
Python programs. (Only interactive sessions execute the script
-specified in the \code{PYTHONPATH} environment variable if it exists).
+specified in the \code{PYTHONSTARTUP} environment variable if it exists).
However, some programs or sites may find it convenient to allow users
to have a standard customization file, which gets run when a program