diff --git a/Doc/lib/libmarshal.tex b/Doc/lib/libmarshal.tex
index d3dd8353472..63ff3926173 100644
--- a/Doc/lib/libmarshal.tex
+++ b/Doc/lib/libmarshal.tex
@@ -109,8 +109,9 @@ In addition, the following constants are defined:
 
 \begin{datadesc}{version}
   Indicates the format that the module uses. Version 0 is the
-  historical format, version 1 (added in Python 2.4) shares
-  interned strings. The current version is 1.
+  historical format, version 1 (added in Python 2.4) shares interned
+  strings and version 2 (added in Python 2.5) uses a binary format for
+  floating point numbers. The current version is 2.
 
   \versionadded{2.4}
-\end{datadesc}
\ No newline at end of file
+\end{datadesc}