diff --git a/index.html b/index.html
index 7910367..fa014b8 100644
--- a/index.html
+++ b/index.html
@@ -66,7 +66,7 @@ Keyboard controls: 'z' to zoom in, 'x' to zoom out, 'n' to step the simulation.
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 Mouse controls: Left-click and drag to scroll around (when you're zoomed in.)
 <br />
-More information in the <a href="http://visual6502.org/wiki/index.php?title=JssimUserHelp">User Guide</a>.
+More information in the <a href="https://web.archive.org/web/20210608195625/http://visual6502.org/wiki/index.php?title=JssimUserHelp">User Guide</a>.
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 </span>