diff --git a/.github/workflows/build-pdf.yml b/.github/workflows/build-pdf.yml
index 2413d2d..52b648f 100644
--- a/.github/workflows/build-pdf.yml
+++ b/.github/workflows/build-pdf.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Install TeX Live
-        run: sudo apt install texlive-full
+        run: sudo apt update && sudo apt install texlive-full
       - name: Checkout code
         uses: actions/checkout@v2
       - name: Build pdf