diff --git a/README.md b/README.md
index e8338ad..c71acab 100644
--- a/README.md
+++ b/README.md
@@ -22,3 +22,15 @@ change it and stop automatic checks.
 You can use `adict-change-dictionary-hook` to hook into any of these changes,
 or `adict-conditional-insert` to insert text (like signatures) that will
 automatically conform to the language.
+
+To limit the candidate languages when guessing which dictionary to use, add
+something like the following to your Emacs config:
+```elisp
+(eval-after-load "auto-dictionary"
+  '(setq adict-dictionary-list
+        (mapcar 'adict--guess-dictionary-cons
+                '(("en" . "en")
+                  ("fr" . "fr")))))
+```
+Get the full list from `adict-dictionary-list` in auto-dictionary.el, or
+alternatively use the Customize interface to do this.