diff --git a/Doc/lib/libposixpath.tex b/Doc/lib/libposixpath.tex
index d0bb73b..11a5740 100644
--- a/Doc/lib/libposixpath.tex
+++ b/Doc/lib/libposixpath.tex
@@ -123,7 +123,10 @@
 an absolute path, all previous components are thrown away, and joining
 continues.  The return value is the concatenation of \var{path1}, and
 optionally \var{path2}, etc., with exactly one slash (\code{'/'})
-inserted between components, unless \var{path} is empty.
+inserted between components, unless \var{path} is empty.  Note that on
+Windows, since there is a current directory for each drive,
+{}\function{os.path.join("c:", "foo")} represents a path relative to the
+current directory on drive C:, not \code{c:\\foo}.
 \end{funcdesc}
 
 \begin{funcdesc}{normcase}{path}