diff --git a/Doc/lib/libtest.tex b/Doc/lib/libtest.tex
index d13bfff..811d2f7 100644
--- a/Doc/lib/libtest.tex
+++ b/Doc/lib/libtest.tex
@@ -266,6 +266,8 @@
 \begin{funcdesc}{guard_warnings_filter}{}
 Returns a context manager that guards the \module{warnings} module's
 filter settings.
+\versionadded{2.6}
+\end{funcdesc}
 
 \begin{funcdesc}{run_unittest}{*classes}
 Execute \class{unittest.TestCase} subclasses passed to the function.