diff --git a/Makefile b/Makefile
index 0e73ea853d8e6966e822ae98ef2ca7914a84aee4..f11ad5d547c90df5fc8245ae49d07e58a8519525 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 all: coverage lint
 
 install:
-	apt-get -y install awscli python3-boto3 python3-pydantic python3-tabulate restic yamllint
+	apt-get -y install awscli python3-boto3 python3-pydantic python3-tabulate restic
 
 install-dev:
-	apt-get -y install python3-venv snapd
+	apt-get -y install python3-venv snapd yamllint
 	python3 -m venv venv
 	venv/bin/pip install -U pip
 	venv/bin/pip install -r requirements.lock
@@ -19,7 +19,7 @@ lint-py:
 	python3 -m pylint rwm.py tests scripts
 
 lint-yaml:
-	yamllint --strict .
+	yamllint --strict . examples/*.conf
 
 test:
 	# show stderr with "-o log_cli=true"
diff --git a/examples/rwm-admin.conf b/examples/rwm-admin.conf
index 9d538726adbf57afc8f09a4e10597b76676a9ad0..a1681d0fc12d33510e5aad511b54414297702666 100644
--- a/examples/rwm-admin.conf
+++ b/examples/rwm-admin.conf
@@ -1,5 +1,5 @@
 # rwm aws, storage
-
+---
 s3_endpoint_url: ""
 s3_access_key: ""
 s3_secret_key: ""
diff --git a/examples/rwm-backups.conf b/examples/rwm-backups.conf
index ffd27165dc3f2f739daca5b47cb82f826e418422..6f8d7ae7aecec77bde69cd675a66c6bc8ecc59f2 100644
--- a/examples/rwm-backups.conf
+++ b/examples/rwm-backups.conf
@@ -1,5 +1,5 @@
 # rwm aws, restic, backup, backup_all
-
+---
 s3_endpoint_url: ""
 s3_access_key: ""
 s3_secret_key: ""
diff --git a/examples/rwm-linux.conf b/examples/rwm-linux.conf
index 35d4874dab77eccb4212b7bab69bac2bd6f7f0a5..1d54c929c6eba19303fa0b2c441ad5fa0c21a50e 100644
--- a/examples/rwm-linux.conf
+++ b/examples/rwm-linux.conf
@@ -1,5 +1,5 @@
 # rwm aws, restic, backup, backup_all
-
+---
 s3_endpoint_url: ""
 s3_access_key: ""
 s3_secret_key: ""
@@ -12,8 +12,8 @@ backups:
     filesdirs:
       - "/"
     excludes:
-      #- "*.cache"
-      #- "*.log"
+      # - "*.cache"
+      # - "*.log"
       - "/dev/*"
       - "/home/*/.cache/*"
       - "/media/*"
diff --git a/examples/rwm-restic.conf b/examples/rwm-restic.conf
index fab285160046e109f1ced991ca9745499cbb8d71..00156e284c732609b5483becdc9ec63bea28f019 100644
--- a/examples/rwm-restic.conf
+++ b/examples/rwm-restic.conf
@@ -1,5 +1,5 @@
 # rwm aws, restic
-
+---
 s3_endpoint_url: ""
 s3_access_key: ""
 s3_secret_key: ""
diff --git a/rwm.py b/rwm.py
index bba8b8a191c5c99b9a3336f6005c2f6829838b43..4012451fc349d5064dc42acbbc34aaeca389c337 100755
--- a/rwm.py
+++ b/rwm.py
@@ -120,7 +120,7 @@ class RWMConfig(BaseModel):
             Dictionary containing named backup configurations.
 
         retention:
-            Dictionary containing retention policies for Restic repository. 
+            Dictionary containing retention policies for Restic repository.
             Keys and values corresponds to a `restic forget` command `--keep*` options without leading dashes.
     """