diff --git a/.github/workflows/doxygen.yml b/.github/workflows/doxygen.yml
index 3294fc5..5b872df 100644
--- a/.github/workflows/doxygen.yml
+++ b/.github/workflows/doxygen.yml
@@ -9,6 +9,7 @@ jobs:
   build-documentation:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v4
     - name: Install Doxygen and Dot
       run: sudo apt install doxygen graphviz
     - name: Run doxygen