diff --git a/README.md b/README.md
index 6873372..cc51cfd 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@ tests with:
 ```
 $ bundle
 $ bundle exec rake
+$ bundle exec rake test <relative-path>  # to run a subset of tests
 ```
 
 Most tests should pass. (If a few tests fail, that's okay. Some of the tests are
diff --git a/Rakefile b/Rakefile
index be6d2cb..d084fa5 100644
--- a/Rakefile
+++ b/Rakefile
@@ -3,9 +3,10 @@ require "rake/testtask"
 Rake::TestTask.new(:test) do |t|
   t.libs << "smells"
   t.libs << "support/ruby"
+  tests = ARGV[1] || "smells/**/*.rb"
   t.test_files = FileList[
     "support/ruby/helper.rb",
-    "smells/**/*.rb"
+    tests
   ]
 end