diff --git a/python/mozlint/test/linters/badreturncode.yml b/python/mozlint/test/linters/badreturncode.yml
index 301d77583dc0..72abf83cc75c 100644
--- a/python/mozlint/test/linters/badreturncode.yml
+++ b/python/mozlint/test/linters/badreturncode.yml
@@ -1,3 +1,4 @@
+---
 BadReturnCodeLinter:
     description: Returns an error code no matter what
     include:
diff --git a/python/mozlint/test/linters/explicit_path.yml b/python/mozlint/test/linters/explicit_path.yml
index 27cf3df7ffeb..80630518993a 100644
--- a/python/mozlint/test/linters/explicit_path.yml
+++ b/python/mozlint/test/linters/explicit_path.yml
@@ -1,3 +1,4 @@
+---
 ExplicitPathLinter:
     description: Only lint a specific file name
     rule: no-foobar
diff --git a/python/mozlint/test/linters/external.yml b/python/mozlint/test/linters/external.yml
index e8e5f1bd40ab..574b8df4cb47 100644
--- a/python/mozlint/test/linters/external.yml
+++ b/python/mozlint/test/linters/external.yml
@@ -1,3 +1,4 @@
+---
 ExternalLinter:
     description: It's bad to have the string foobar in js files.
     include:
diff --git a/python/mozlint/test/linters/invalid_exclude.yml b/python/mozlint/test/linters/invalid_exclude.yml
index c6e235f9e430..7231d2c14643 100644
--- a/python/mozlint/test/linters/invalid_exclude.yml
+++ b/python/mozlint/test/linters/invalid_exclude.yml
@@ -1,3 +1,4 @@
+---
 BadExcludeLinter:
     description: Has an invalid exclude directive.
     exclude: [0, 1]  # should be a list of strings
diff --git a/python/mozlint/test/linters/invalid_extension.ym b/python/mozlint/test/linters/invalid_extension.ym
index 7dac964fe66e..435fa10320f3 100644
--- a/python/mozlint/test/linters/invalid_extension.ym
+++ b/python/mozlint/test/linters/invalid_extension.ym
@@ -1,3 +1,4 @@
+---
 BadExtensionLinter:
     description: Has an invalid file extension.
     type: string
diff --git a/python/mozlint/test/linters/invalid_include.yml b/python/mozlint/test/linters/invalid_include.yml
index 1d16db31627e..b76b3e6a61d7 100644
--- a/python/mozlint/test/linters/invalid_include.yml
+++ b/python/mozlint/test/linters/invalid_include.yml
@@ -1,3 +1,4 @@
+---
 BadIncludeLinter:
     description: Has an invalid include directive.
     include: should be a list
diff --git a/python/mozlint/test/linters/invalid_type.yml b/python/mozlint/test/linters/invalid_type.yml
index fd47252f606f..29d82e541e1a 100644
--- a/python/mozlint/test/linters/invalid_type.yml
+++ b/python/mozlint/test/linters/invalid_type.yml
@@ -1,3 +1,4 @@
+---
 BadTypeLinter:
     description: Has an invalid type.
     type: invalid
diff --git a/python/mozlint/test/linters/missing_attrs.yml b/python/mozlint/test/linters/missing_attrs.yml
index a62425582154..5abe15fcfc59 100644
--- 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
diff --git a/python/mozlint/test/linters/raises.yml b/python/mozlint/test/linters/raises.yml
index d9696f351a76..534896151373 100644
--- a/python/mozlint/test/linters/raises.yml
+++ b/python/mozlint/test/linters/raises.yml
@@ -1,3 +1,4 @@
+---
 RaisesLinter:
     description: Raises an exception
     type: external
diff --git a/python/mozlint/test/linters/regex.yml b/python/mozlint/test/linters/regex.yml
index 570bbd98080b..5b0f11bd830b 100644
--- a/python/mozlint/test/linters/regex.yml
+++ b/python/mozlint/test/linters/regex.yml
@@ -1,5 +1,8 @@
+---
 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'
diff --git a/python/mozlint/test/linters/string.yml b/python/mozlint/test/linters/string.yml
index 2253a3bbd0e4..1202c5728b33 100644
--- a/python/mozlint/test/linters/string.yml
+++ b/python/mozlint/test/linters/string.yml
@@ -1,5 +1,8 @@
+---
 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'
diff --git a/python/mozlint/test/linters/structured.yml b/python/mozlint/test/linters/structured.yml
index a2cbe56ecefa..01ef447ee3bd 100644
--- a/python/mozlint/test/linters/structured.yml
+++ b/python/mozlint/test/linters/structured.yml
@@ -1,3 +1,4 @@
+---
 StructuredLinter:
     description: "It's bad to have the string foobar in js files."
     include:
diff --git a/tools/lint/yaml.yml b/tools/lint/yaml.yml
index 32d26ee51bc9..a4ad5547f1a1 100644
--- a/tools/lint/yaml.yml
+++ b/tools/lint/yaml.yml
@@ -2,6 +2,7 @@ yamllint:
     description: YAML linter
     include:
         - .cron.yml
+        - python/mozlint/
         - taskcluster
     extensions: ['yml', 'yaml']
     type: external