diff --git a/.gitea/workflows/build-pdf.yaml b/.gitea/workflows/build-pdf.yaml
index 9ce04d0..2132191 100644
--- a/.gitea/workflows/build-pdf.yaml
+++ b/.gitea/workflows/build-pdf.yaml
@@ -21,7 +21,9 @@ jobs:
         run: npm install -g @marp-team/marp-cli
 
       - name: Install chromium
-        run: sudo apt-get install -y chromium-browser
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y chromium-browser
 
       - name: Build PDF
         run: marp main.md --pdf