diff --git a/.autotest b/.autotest
new file mode 100644
index 0000000..7087fe3
--- /dev/null
+++ b/.autotest
@@ -0,0 +1,5 @@
+Autotest.add_hook :initialize do |at|
+  at.add_mapping(%r%^test/.+_test.rb$%) do |filename, _|
+    filename
+  end
+end
\ No newline at end of file