diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7038d08d..28784430 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -9,7 +9,7 @@ env:
 
 jobs:
   build-publish-pdf:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
 
     steps:
     - uses: actions/checkout@v2