--- a/python/mozlint/test/linters/badreturncode.yml
+++ b/python/mozlint/test/linters/badreturncode.yml
@@ -1,7 +1,8 @@
+---
 BadReturnCodeLinter:
     description: Returns an error code no matter what
     include:
         - files
     type: external
     extensions: ['.js', '.jsm']
     payload: external:badreturncode

--- a/python/mozlint/test/linters/explicit_path.yml
+++ b/python/mozlint/test/linters/explicit_path.yml
@@ -1,7 +1,8 @@
+---
 ExplicitPathLinter:
     description: Only lint a specific file name
     rule: no-foobar
     include:
         - no_foobar.js
     type: string
     payload: foobar

--- a/python/mozlint/test/linters/external.yml
+++ b/python/mozlint/test/linters/external.yml
@@ -1,7 +1,8 @@
+---
 ExternalLinter:
     description: It's bad to have the string foobar in js files.
     include:
         - files
     type: external
     extensions: ['.js', '.jsm']
     payload: external:external

--- a/python/mozlint/test/linters/invalid_exclude.yml
+++ b/python/mozlint/test/linters/invalid_exclude.yml
@@ -1,5 +1,6 @@
+---
 BadExcludeLinter:
     description: Has an invalid exclude directive.
     exclude: [0, 1]  # should be a list of strings
     type: string
     payload: foobar

--- a/python/mozlint/test/linters/invalid_extension.ym
+++ b/python/mozlint/test/linters/invalid_extension.ym
@@ -1,4 +1,5 @@
+---
 BadExtensionLinter:
     description: Has an invalid file extension.
     type: string
     payload: foobar

--- a/python/mozlint/test/linters/invalid_include.yml
+++ b/python/mozlint/test/linters/invalid_include.yml
@@ -1,5 +1,6 @@
+---
 BadIncludeLinter:
     description: Has an invalid include directive.
     include: should be a list
     type: string
     payload: foobar

--- a/python/mozlint/test/linters/invalid_type.yml
+++ b/python/mozlint/test/linters/invalid_type.yml
@@ -1,4 +1,5 @@
+---
 BadTypeLinter:
     description: Has an invalid type.
     type: invalid
     payload: foobar

--- a/python/mozlint/test/linters/missing_attrs.yml
+++ b/python/mozlint/test/linters/missing_attrs.yml
@@ -1,2 +1,3 @@
+---
 MissingAttrsLinter:
     description: Missing type and payload

--- a/python/mozlint/test/linters/raises.yml
+++ b/python/mozlint/test/linters/raises.yml
@@ -1,4 +1,5 @@
+---
 RaisesLinter:
     description: Raises an exception
     type: external
     payload: external:raises

--- a/python/mozlint/test/linters/regex.yml
+++ b/python/mozlint/test/linters/regex.yml
@@ -1,8 +1,11 @@
+---
 RegexLinter:
-    description: Make sure the string foobar never appears in a js variable file because it is bad.
+    description: >-
+        Make sure the string foobar never appears in a js variable
+        file because it is bad.
     rule: no-foobar
     include:
         - '**/*.js'
         - '**/*.jsm'
     type: regex
     payload: foobar

--- a/python/mozlint/test/linters/string.yml
+++ b/python/mozlint/test/linters/string.yml
@@ -1,9 +1,12 @@
+---
 StringLinter:
-    description: Make sure the string foobar never appears in browser js files because it is bad
+    description: >-
+        Make sure the string foobar never appears in browser js
+        files because it is bad
     rule: no-foobar
     include:
         - '**/*.js'
         - '**/*.jsm'
     type: string
     extensions: ['.js', 'jsm']
     payload: foobar

--- a/python/mozlint/test/linters/structured.yml
+++ b/python/mozlint/test/linters/structured.yml
@@ -1,7 +1,8 @@
+---
 StructuredLinter:
     description: "It's bad to have the string foobar in js files."
     include:
         - files
     type: structured_log
     extensions: ['.js', '.jsm']
     payload: external:structured

--- a/tools/lint/yaml.yml
+++ b/tools/lint/yaml.yml
@@ -1,8 +1,9 @@
 yamllint:
     description: YAML linter
     include:
         - .cron.yml
+        - python/mozlint/
         - taskcluster
     extensions: ['yml', 'yaml']
     type: external
     payload: yamllint_:lint