diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4769478..64f7a82 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -21,6 +21,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+      - name: install graphviz
+        uses: tlylt/install-graphviz@v1
       - name: Set up Python
         uses: actions/setup-python@v3
         with: