diff --git a/.mdlrc b/.mdlrc
new file mode 100644
index 0000000..60ecd7f
--- /dev/null
+++ b/.mdlrc
@@ -0,0 +1,2 @@
+# Disable "MD013 Line length" and "MD029 Ordered list item prefix".
+rules "~MD013", "~MD029"
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..1950f8a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,13 @@
+.PHONY: check phpstan phpcs markdownlint
+
+check: phpstan phpcs markdownlint
+
+phpstan:
+	-vendor/bin/phpstan analyse .
+
+phpcs:
+	-vendor/bin/phpcs -s bin/ src/
+
+# gem install mdl
+markdownlint:
+	-mdl *.md