diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yaml
similarity index 91%
rename from .github/workflows/build-docs.yml
rename to .github/workflows/build-docs.yaml
index c375906d..0e4e18ac 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yaml
@@ -3,8 +3,10 @@ name: Build Documentation
 on:
   push:
     branches:
-      - master
       - main
+    paths:
+      - .github/workflows/build-docs.yaml
+      - docs/**
 permissions:
   contents: write
 jobs:
@@ -22,8 +24,8 @@ jobs:
         with:
           key: ${{ github.ref }}
           path: .cache
-      - run: pip install -r requirements.txt
-      - run: mkdocs gh-deploy --force
+      - run: pip install -r docs/requirements.txt
+      - run: cd docs && mkdocs gh-deploy --force
         # Ref: https://github.com/ojacques/mkdocs-git-committers-plugin-2
         # Ref: https://github.com/ojacques/mkdocs-git-committers-plugin-2/issues/51#issuecomment-1951450239
         env:
diff --git a/tests/lint_workflows.py b/tests/lint_workflows.py
index f73cc735..4b44119c 100644
--- a/tests/lint_workflows.py
+++ b/tests/lint_workflows.py
@@ -15,3 +15,6 @@
         if content.count("@master") != content.count("master"):
             # Ref: https://github.com/j3soon/ros2-essentials/pull/44#pullrequestreview-2251404984
             raise ValueError(f"`master` should not exist since it's obsolete: '{filename}'")
+for filename in glob.glob(f"{repo_dir}/.github/workflows/*.yml"):
+    logging.debug(f"Checking: '{filename[len(repo_dir)+1:]}'...")
+    raise ValueError(f"workflows should use `.yaml` files instead of `.yml` files: '{filename}'")