Add \exception markup
diff --git a/Doc/lib/libthread.tex b/Doc/lib/libthread.tex
index 9e0c202..9573ab3 100644
--- a/Doc/lib/libthread.tex
+++ b/Doc/lib/libthread.tex
@@ -44,8 +44,8 @@
\end{funcdesc}
\begin{funcdesc}{interrupt_main}{}
-Raise a KeyboardInterrupt in the main thread. A subthread can use this
-function to interrupt the main thread.
+Raise a \exception{KeyboardInterrupt} exception in the main thread. A subthread
+can use this function to interrupt the main thread.
\versionadded{2.3}
\end{funcdesc}