diff --git a/README.md b/README.md
index 33bb122..2d5be53 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,19 @@
 > Tools to help Rails developers test
 
 Find something nice, [browse files in the rails-testing-toolbox project root](https://github.com/eliotsykes/rails-testing-toolbox).
+
+# Installation notes
+
+These files are designed to be placed in the `specs/support/` subdirectory.
+
+If you haven't used support files yet, you may want to uncomment the following line in `specs/rails_helper.rb`:
+
+```diff
+ # The following line is provided for convenience purposes. It has the downside
+ # of increasing the boot-up time by auto-requiring all files in the support
+ # directory. Alternatively, in the individual `*_spec.rb` files, manually
+ # require only the support files necessary.
+ #
+-# Dir[Rails.root.join('spec', 'support', '**', '*.rb')].each { |f| require f }
++Dir[Rails.root.join('spec', 'support', '**', '*.rb')].each { |f| require f }
+```