diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 7d6e1fc7..5c99691d 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -24,7 +24,7 @@ jobs:
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
       - name: Run tests
-        run: nix develop --command -- poetry run mkdocs build --strict
+        run: nix develop --command -- poetry install && poetry run mkdocs build --strict
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3
         with:
diff --git a/flake.nix b/flake.nix
index 83081429..d7263916 100644
--- a/flake.nix
+++ b/flake.nix
@@ -95,6 +95,7 @@
           python311
           poetry
           mkdocs
+          cairo
         ];
 
       # Add entry to build a docker image with headscale
diff --git a/poetry.lock b/poetry.lock
index e1819ca7..4769298d 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1015,4 +1015,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.11"
-content-hash = "41e982f54f4dd5c6d686cd2482fbf882bf7b30e566670e96de00e77f5c611d31"
+content-hash = "11fb159dd50e4d55255a52ae506f4dd23a52e00d30ade481b6bd9a13687bcd25"