diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..4e7bce5
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,3 @@
+## Build and test
+
+Please follow the ["Making Changes To Standard Libraries"](https://docs.ruby-lang.org/en/master/contributing/making_changes_to_stdlibs_md.html) guideline.
diff --git a/README.md b/README.md
index 1a857d2..b74c6bc 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ FileUtils.pwd
 # => "/usr/bin"
 ```
 
-You can find a full method list in the [documentation](https://ruby-doc.org/stdlib/libdoc/fileutils/rdoc/FileUtils.html).
+You can find a full method list in the [documentation](https://docs.ruby-lang.org/en/master/FileUtils.html).
 
 ## Contributing