diff --git a/test/README.md b/test/README.md
new file mode 100644
index 000000000..4b73af8c4
--- /dev/null
+++ b/test/README.md
@@ -0,0 +1,3 @@
+# Naming
+
+Only files matching `*_test.rb` will be executed as tests.
diff --git a/test/cask/dsl/before_uninstall.rb b/test/cask/dsl/before_uninstall_test.rb
similarity index 100%
rename from test/cask/dsl/before_uninstall.rb
rename to test/cask/dsl/before_uninstall_test.rb