diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex
index 6355731..c464517 100644
--- a/Doc/lib/libstdtypes.tex
+++ b/Doc/lib/libstdtypes.tex
@@ -1075,7 +1075,7 @@
   no longer works in Python 2.0.  Use of this misfeature has been
   deprecated since Python 1.4.
 
-\item[(3)] Raises an exception when \var{x} is not a list object.
+\item[(3)] \var{x} can be any iterable object.
 
 \item[(4)] Raises \exception{ValueError} when \var{x} is not found in
   \var{s}. When a negative index is passed as the second or third parameter