diff --git a/.github/workflows/docs.yaml b/.github/workflows/docs.yaml
index 3a32366..74268c0 100644
--- a/.github/workflows/docs.yaml
+++ b/.github/workflows/docs.yaml
@@ -22,7 +22,7 @@ jobs:
         with:
           python-version: 3.x
       - name: Install plantuml
-        run: sudo apt-get install -y plantuml
+        run: sudo apt-get update && sudo apt-get install -y plantuml
       - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
       - uses: actions/cache@v4
         with: