diff --git a/.github/workflows/makefile.yml b/.github/workflows/makefile.yml
index 3350abb..fc2222e 100644
--- a/.github/workflows/makefile.yml
+++ b/.github/workflows/makefile.yml
@@ -1,10 +1,11 @@
+---
 name: Makefile CI
 
-on:
+"on":
   push:
-    branches: [ "main" ]
+    branches: ["main"]
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 jobs:
   build:
@@ -12,7 +13,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
-
-    - name: Run make all
-      run: make all
+      - uses: actions/checkout@v3
+      - name: Run make all
+        run: make all
diff --git a/Makefile b/Makefile
index bd41dd8..fd512c6 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@ PY = python3
 VENV = venv
 BIN=$(ROOT_DIR)/$(VENV)/bin
 
-all: bashate shellcheck test
+all: bashate shellcheck test yamllint
 
 $(VENV): requirements.txt
 	$(PY) -m venv $(VENV)
@@ -29,6 +29,10 @@ shellcheck: $(VENV)
 test:
 	$(ROOT_DIR)/test/test.sh
 
+.PHONY: yamllint
+yamllint: $(VENV)
+	$(BIN)/yamllint .
+
 clean:
 	rm -rf $(VENV)
 	find . -type f -name *.pyc -delete
diff --git a/requirements.txt b/requirements.txt
index 300a915..a9bf098 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 bashate
 shellcheck-py
+yamllint