diff --git a/Doc/lib/libcsv.tex b/Doc/lib/libcsv.tex
index 02a176c..e965e31 100644
--- a/Doc/lib/libcsv.tex
+++ b/Doc/lib/libcsv.tex
@@ -345,6 +345,7 @@
 \begin{memberdesc}[csv reader]{line_num}
  The number of lines read from the source iterator. This is not the same
  as the number of records returned, as records can span multiple lines.
+ \versionadded{2.5}
 \end{memberdesc}