diff --git a/contrib/filter-repo-demos/lint-history b/contrib/filter-repo-demos/lint-history
index a9630c6..0695a08 100755
--- a/contrib/filter-repo-demos/lint-history
+++ b/contrib/filter-repo-demos/lint-history
@@ -59,6 +59,9 @@ example_text = '''CALLBACK
         def is_relevant(filename):
             BODY
 
+    Where filename is the full relative path from the toplevel of the
+    repository.
+
     Thus, to only run on files with a ".txt" extension you would run
         lint-history --relevant 'return filename.endswith(b".txt")' ...