diff --git a/MANIFEST.in b/MANIFEST.in
index a64eb62..d1135e9 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,3 +1,4 @@
 include README.md
 include LICENSE.md
 include mkdocs_macros/*.md
+include mkdocs_macros/py.typed
diff --git a/README.md b/README.md
index c7b43e3..f9b2cbc 100644
--- a/README.md
+++ b/README.md
@@ -142,6 +142,20 @@ you should also add the `search` plugin.
 If no `plugins` entry is set, MkDocs enables `search` by default; but
 if you use it, then you have to declare it explicitly.
 
+By default, undefined variables are printed to the page as-is. If you
+wish for a page to fail on undefined variables, you should use the
+below configuration instead:
+
+```yaml
+plugins:
+    - search
+    - macros
+          on_undefined: strict
+```
+
+For details and more options, see the [documentation](
+https://mkdocs-macros-plugin.readthedocs.io/en/latest/troubleshooting/#what-happens-if-a-variable-is-undefined).
+
 ### Check that it works
 The recommended way to check that the plugin works properly is to add the 
 following command in one of the pages of your site (let's say `info.md`):
diff --git a/mkdocs_macros/plugin.py b/mkdocs_macros/plugin.py
index 00aa362..d3f5b66 100644
--- a/mkdocs_macros/plugin.py
+++ b/mkdocs_macros/plugin.py
@@ -373,7 +373,7 @@ def _load_yaml(self):
             # Paths are be relative to the project root.
             filename = os.path.join(self.project_dir, filename)
             if os.path.isfile(filename):
-                with open(filename) as f:
+                with open(filename, encoding="utf-8") as f:
                     # load the yaml file
                     # NOTE: for the SafeLoader argument, see: https://github.com/yaml/pyyaml/wiki/PyYAML-yaml.load(input)-Deprecation
                     content = yaml.load(f, Loader=yaml.SafeLoader)
diff --git a/mkdocs_macros/py.typed b/mkdocs_macros/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/setup.py b/setup.py
index e17626f..508ed57 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
 
 def read_file(fname):
     "Read a local file"
-    return open(os.path.join(os.path.dirname(__file__), fname)).read()
+    return open(os.path.join(os.path.dirname(__file__), fname), encoding="utf-8").read()
 
 
 setup(