diff --git a/.copier-answers.yml b/.copier-answers.yml
index ab242b1c..c720007f 100644
--- a/.copier-answers.yml
+++ b/.copier-answers.yml
@@ -1,5 +1,5 @@
 # Changes here will be overwritten by Copier
-_commit: 0.16.4
+_commit: 0.16.6
 _src_path: gh:pawamoy/copier-pdm.git
 author_email: pawamoy@pm.me
 author_fullname: Timothée Mazzucotelli
diff --git a/docs/css/mkdocstrings.css b/docs/css/mkdocstrings.css
index 2db20680..3960e49e 100644
--- a/docs/css/mkdocstrings.css
+++ b/docs/css/mkdocstrings.css
@@ -9,6 +9,7 @@ a.external::after,
 a.autorefs-external::after {
   /* https://primer.style/octicons/arrow-up-right-24 */
   mask-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18.25 15.5a.75.75 0 00.75-.75v-9a.75.75 0 00-.75-.75h-9a.75.75 0 000 1.5h7.19L6.22 16.72a.75.75 0 101.06 1.06L17.5 7.56v7.19c0 .414.336.75.75.75z"></path></svg>');
+  -webkit-mask-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18.25 15.5a.75.75 0 00.75-.75v-9a.75.75 0 00-.75-.75h-9a.75.75 0 000 1.5h7.19L6.22 16.72a.75.75 0 101.06 1.06L17.5 7.56v7.19c0 .414.336.75.75.75z"></path></svg>');
   content: ' ';
 
   display: inline-block;
diff --git a/docs/insiders/index.md b/docs/insiders/index.md
index 3a55ad5d..bfb2d428 100644
--- a/docs/insiders/index.md
+++ b/docs/insiders/index.md
@@ -219,7 +219,7 @@ by the [ISC License][license]. However, we kindly ask you to respect our
 [goals completed]: #goals-completed
 [github sponsor profile]: https://github.com/sponsors/pawamoy
 [billing cycle]: https://docs.github.com/en/github/setting-up-and-managing-billing-and-payments-on-github/changing-the-duration-of-your-billing-cycle
-[license]: ../license/
+[license]: ../license.md
 [private forks]: https://docs.github.com/en/github/setting-up-and-managing-your-github-user-account/removing-a-collaborator-from-a-personal-repository
 
 <script src="../js/insiders.js"></script>
diff --git a/docs/insiders/installation.md b/docs/insiders/installation.md
index 368f1b47..b7af7d2e 100644
--- a/docs/insiders/installation.md
+++ b/docs/insiders/installation.md
@@ -107,7 +107,7 @@ or installing a package (with pip), and depending on the registry you are using
 Please check the documentation of your registry to learn how to configure your environment.
 
 **We kindly ask that you do not upload the distributions to public registries,
-as it is against our [Terms of use](../#terms).**
+as it is against our [Terms of use](index.md#terms).**
 
 >? TIP: **Full example with `pypiserver`**  
 > In this example we use [pypiserver] to serve a local PyPI index.
diff --git a/duties.py b/duties.py
index 2e1248bf..644b2ffb 100644
--- a/duties.py
+++ b/duties.py
@@ -53,10 +53,10 @@ def merge(d1: Any, d2: Any) -> Any:  # noqa: D103
 
 
 def mkdocs_config() -> str:  # noqa: D103
-    from mkdocs import utils
+    import mergedeep
 
-    # patch YAML loader to merge arrays
-    utils.merge = merge
+    # force YAML loader to merge arrays
+    mergedeep.merge = merge
 
     if "+insiders" in pkgversion("mkdocs-material"):
         return "mkdocs.insiders.yml"
diff --git a/mkdocs.yml b/mkdocs.yml
index d7500280..65541ffc 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -8,6 +8,11 @@ watch: [mkdocs.yml, README.md, CONTRIBUTING.md, CHANGELOG.md, src/mkdocstrings]
 copyright: Copyright &copy; 2019 Timothée Mazzucotelli
 edit_uri: edit/main/docs/
 
+validation:
+  omitted_files: warn
+  absolute_links: warn
+  unrecognized_links: warn
+
 nav:
 - Home:
   - Overview: index.md
diff --git a/pyproject.toml b/pyproject.toml
index 57f09f4d..78af6bff 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -75,7 +75,7 @@ docs = [
     "black>=23.1",
     "markdown-callouts>=0.2",
     "markdown-exec>=0.5",
-    "mkdocs>=1.3",
+    "mkdocs>=1.5",
     "mkdocs-coverage>=0.2",
     "mkdocs-gen-files>=0.3",
     "mkdocs-git-committers-plugin-2>=1.1",