diff --git a/doc/plugin/MagicCombo.md b/doc/plugin/MagicCombo.md
index 2e240222..6a3256e6 100644
--- a/doc/plugin/MagicCombo.md
+++ b/doc/plugin/MagicCombo.md
@@ -83,6 +83,9 @@ and we'll help you with it.
  [gh:issues]: https://github.com/keyboardio/Kaleidoscope/issues
  [forums]: https://community.keyboard.io/
 
+Trying to use the old API errors out with a helpful error message, but as the
+old API is deprecated, this will be removed by 2019-01-14.
+
 ## The old API
 
 ```c++