diff --git a/beetsplug/lastgenre/__init__.py b/beetsplug/lastgenre/__init__.py
index 5dbfaefb9..e9dfe634c 100644
--- a/beetsplug/lastgenre/__init__.py
+++ b/beetsplug/lastgenre/__init__.py
@@ -242,7 +242,9 @@ class LastGenrePlugin(plugins.BeetsPlugin):
     def _cached_lookup(self, entity, method, *args):
         """Get a genre based on the named entity using the callable `method`
         whose arguments are given in the sequence `args`. The genre lookup
-        is cached based on the entity name and the arguments.
+        is cached based on the entity name and the arguments. Before the lookup,
+        each argument is has some Unicode characters replaced with rough ASCII
+        equivalents in order to return better results from the Last.fm database.
         """
         # Shortcut if we're missing metadata.
         if any(not s for s in args):