diff --git a/Doc/lib/libsocket.tex b/Doc/lib/libsocket.tex
index 0b9b789..f0b7f8b 100644
--- a/Doc/lib/libsocket.tex
+++ b/Doc/lib/libsocket.tex
@@ -109,6 +109,7 @@
 available.  The first name which includes a period is selected.  In
 case no fully qualified domain name is available, the hostname is
 returned.
+\versionadded{2.0}
 \end{funcdesc}
 
 \begin{funcdesc}{gethostbyname}{hostname}