diff --git a/doc/cbm510.sgml b/doc/cbm510.sgml
index 012a7b596..c208f3ead 100644
--- a/doc/cbm510.sgml
+++ b/doc/cbm510.sgml
@@ -126,6 +126,7 @@ declaration and usage.
 <item>cbm_save
 <item>cbm_write
 <item>get_tv
+<item>waitvsync
 </itemize>