diff --git a/docs/17-porting-tips.md b/docs/17-porting-tips.md
index c391a0aa..3b413e7f 100644
--- a/docs/17-porting-tips.md
+++ b/docs/17-porting-tips.md
@@ -8,6 +8,13 @@ The
 you might have added to your `rc.lua`.
 This avoids most of the possible errors due to missing important changes.
 
+To do this, you can download the default rc.lua for 3.5.9
+[here](https://github.com/awesomeWM/awesome/blob/v3.5.9/awesomerc.lua.in), and
+then compare your existing rc.lua with the 3.5.9 default using your diff tool of
+choice. Write down the changes, then apply these to the 4.0 default rc.lua,
+which you can find at /etc/xdg/awesome/rc.lua after the upgrade, or
+[here](../sample%20files/rc.lua.html) if you have not yet performed the upgrade.
+
 If you still wish to ignore this advice, first read the
 <a href="89-NEWS.md.html#v4">NEWS</a> section about the breaking changes. This
 document assumes you did.