diff --git a/M42.mediawiki b/M42.mediawiki
index 407a328..d1ab985 100644
--- a/M42.mediawiki
+++ b/M42.mediawiki
@@ -9,3 +9,5 @@ Set the state of Pin 9 to 1.
 
 ==== Discussion ====
 M42 immediately changes a hardware pin's state. This can cause bad things to happen if not used correctly. Use with caution!
+
+If you need the pin change to wait for the last-queued move, precede it with [[M400]].