diff --git a/lib/doc/UserGuide.lyx b/lib/doc/UserGuide.lyx
index 12afc9bacd..292f33df21 100644
--- a/lib/doc/UserGuide.lyx
+++ b/lib/doc/UserGuide.lyx
@@ -20658,6 +20658,8 @@ To insert an argument mark (only inside a macro definition box) simply type
 \newline
 
 \family typewriter
+
+\backslash
 #<number>
 \family default
  or use