diff --git a/.mdl_style.rb b/.mdl_style.rb
new file mode 100644
index 0000000..da919b3
--- /dev/null
+++ b/.mdl_style.rb
@@ -0,0 +1,7 @@
+all
+# https://github.com/markdownlint/markdownlint/blob/master/docs/RULES.md#md003---header-style
+rule 'MD003', :style => :setext_with_atx
+# https://github.com/markdownlint/markdownlint/blob/master/docs/RULES.md#md013---line-length
+rule 'MD013', :line_length => 88
+# https://github.com/markdownlint/markdownlint/blob/master/docs/RULES.md#md029---ordered-list-item-prefix
+rule 'MD029', :style => :ordered
diff --git a/.mdlrc b/.mdlrc
new file mode 100644
index 0000000..1f82ca2
--- /dev/null
+++ b/.mdlrc
@@ -0,0 +1 @@
+style '.mdl_style.rb'
diff --git a/contributing.md b/contributing.md
index cb8f14f..9c3a885 100644
--- a/contributing.md
+++ b/contributing.md
@@ -113,6 +113,10 @@ of this repository.
        tests/test_default.yml
        ```
 
+    5. Check the markdown format with
+       [mdl](https://github.com/markdownlint/markdownlint) after changing any
+       markdown document.
+
 4. Once the work is ready and commited, push the branch to your remote fork and click on
    "new Pull Request" on Github.